A tour to a genetic labaratory is organised for the students of the high school where Peter Parker is studying. He shows much interest in sciences and arrives there with great enthusiasm, while the rest students of his class are dull and uninterested. During the tour, a spider, which has been genetically engineered, escapes from its aquarium, and happens accidentally to bite Peter on the hand. At first Peter does not feel any change, but when he arrives home he faints in his room.
In the morning when Peter wakes up, the first thing that astonishes him is the fact that he is no longer near-sighted. All his life he was wearing glasses, and now he sees perfectly without them. The next thing, which astonishes him even more, is his physique. When he looks in the mirror he finds that he is in splendid muscular fit. But along with these pleasant changes, there are ones which bring him some troubles. During the lunch in the school Peter accidentally finds that his wrists are producing webs, and he happens accidentally to throw a tray with food into Flash Thompson, one of the strongest and fiercest bullies in the school. Flash is not going to let such an insult remain and steps into the confrontation with Peter. During the fight Peter learns of other super powers, which he now possesses. Among these are speed, strength, and ability to stick to surfaces. Little needles appear from his fingers, and with their help he can climb the walls.
Meanwhile Peter becomes accustomed to his newly obtained super powers, Norman Osborn (who also happens to be the father of Peter’s friend Harry Osborn), tries to receive a serious military contract, which would let him continue his experiments. But the government does not want these experiments to be held on people, so Norman dares extreme measures, and becomes the first person on whom the experiment is conducted on. As a result he goes insane, his personality is doubled, and in the state of distraction, he kills his an assistant. In the morning Norman remembers nothing of what has happened the night before.
Peter’s life continues to change. He falls in love with a neighbor girl Mary Jane and wants to impress her with a new car, but he has no money. So, to get some money Peter decides to take part in underground fights, where he is confronted with a huge, strong man. Peter wins the battle using his super powers, but the organizer of these fights does not give him the promised money. At that moment a thief raids the office and takes the money. Peter allows the thief to go, as a revenge to the organizer for his lies.
Walking home, Peter witnesses his uncle Ben being robbed and injured right on the street. Uncle Ben dies before the ambulance arrives, and Peter rushes after the perpetrator. Having used his super powers, Peter reaches the murderer quicker than police, and recognizes in him the thief that he has let go from the promoter’s office an hour ago. Peter is frustrated by the feeling of guilt. Peter spends a night pondering over all the events which happened recently, and makes up his mind to fight against injustice in the city.
After the appearance of a superhero in the city, the local newspapers start a pursuit after his photos. Jonah Jameson, the editor of the newspaper, promises pecuniary reward to a person, who will provide the newspaper with photos of newly appeared superhero. Peter Parker brings the photos of the Spider-Man, and is hired as a photographer to this newspaper.
Norman Osborn’s second identity, the one he has obtained after the experiment, takes control over him, and now Norman is conscious of all his deeds. He has turned into a real villain, and kills those who intended to fire him. Norman appears at the Unity Fair disguised as the Green Goblin, so nobody recognizes him as Norman Osborn. Spider-Man manages to rebuff the Goblin but receives a wound.
Few days after, Peter and Harry share Thanksgiving dinner in the apartment where they both live. Norman is also invited and during the dinner he notices the wound on Peter’s arm. He comes to the conclusion that Peter is Spider-Man. Norman also finds out that Peter has feelings for Mary Jane.
Norman Osborn again disguises himself as the Green Goblin, and holds Mary Jane as a hostage. This is too simple for him, so he decides to hold hostage a tram car full of children as well, forcing Spider-Man to choose between Mary Jane and the children in the car. But Peter fortunately saves them all.
After that both superheroes (good and bad) meet in an abandoned building. They engage in cruel combat, but Spider-Man appears to be luckier and manages to disarm the Green Goblin. Peter is unpleasantly shocked when recognizes the person under the mask of the Goblin. Dying Norman begs Peter not to tell Harry the truth. Peter takes Norman’s body to their apartment. That moment Harry enters and encounters Spider-Man, who is standing over the dead body of his father.
The film ends with the funeral of Norman Osborn. At the funeral Harry tells Peter that he is the only family he has now, as there is nobody he can trust. Harry makes a vow to find and kill Spider-Man at any cost.
