We like to think that Spider-Man can be invulnerable due to his spider-sense combined with his strength. Plus he can stick to walls, which certainly comes in handy. However he has been duped many times and despite being strong enough to lift a freight train he has been trapped by villains due to his faults. And being trapped is the best way to judge Spider-Man’s weaknesses since he becomes more useless than a megaphone to a monk who took a vow of silence.
When The Chameleon captured and unmasked Spider-Man he had to keep him caged. We can see this in Spectacular Spider-Man 245. This was no ordinary cage though, as it was electrified. It was at this point that we realize that one of Spider-Man’s weaknesses is electricity, since it was keeping him trapped. But how did he escape though? After Chameleon made it clear that he was pay Mary Jane a visit Spider-Man had to come up with a plan to keep his wife from getting harmed. This is when he decided to make himself a thick pair of gloves out of webbing. With his hands obscured he managed to escape the electrified cage.
This was not the only time when Spider-Man found himself in a sticky situation. The Vulture dropped him into a water tower one time and snapped the lid shut. This happened way back in Amazing Spider-Man issue 2. This is when we found out that water is one of Spider-Man’s weaknesses, as he cannot stick to walls when wet. Spider-Man himself admitted that he was just going to drown to death since he had been rendered powerless. Eventually he realized that he could build up enough force to jump his way out forcefully. However it’s hard to ignore that one of Spider-Man’s weaknesses is plain old water.
More of a character flaw than a weakness, Spider-Man himself has stated that he relies on his spider sense too much. He uses it to know when he is in danger, or if someone is following him. In the case of Venom, he was followed to areas that put himself and others at risk. There was also a time when he relied on his spider sense and assumed that Wolverine was behind him, but in fact wound up spinning around and caving in the face of Wolverine’s girlfriend instead. If you are interested in Spider-Man committing manslaughter, be sure to buy this comic (Affiliate Link) pronto.