Perhaps there aren’t that many costumed crimefighters with press jobs anymore because they’ve found so much employment lately in Hollywood.

“Spider-Man” is one in a long string of mainstream movies based on a popular comic book character (most of them Marvel properties) already in the pipeline. Within the next year, big-screen versions of The Hulk, Daredevil and Ghost Rider are scheduled to open, as will sequels to “X-Men” and, inevitably, “Spider-Man.”

If this faithful rendition of the 1962 Stan Lee/Steve Ditko creation is any indication, Columbia Pictures has a franchise on its hands that could flourish for years. Yet this initial film also demonstrates that there’s plenty of room for improvement.

A seemingly miscast Tobey Maguire stars as high school science geek Peter Parker. Scrawny and with thick glasses (are there any other kind of movie nerds?), he is bullied by classmates, all while pining for the lovely Mary Jane Watson (Kirsten Dunst). His only friend is the equally outcast Harry Osborn (James Franco, who originally auditioned for the lead role but was cast as the sidekick instead.)

When an irradiated super spider bites Peter during a class field trip, he gains the creature’s powers. At first attempting to capitalize financially on these strengths, a personal tragedy compels him into a life of battling evil.

Meanwhile, industrial mogul Norman Osborn (Willem Dafoe) – Harry’s father – is going through a similar transformation. Threatened with the military terminating his contract, he tests an experimental super-soldier formula on himself. The man inherits heightened strength and aggression but with the side effect of insanity. Vowing to “rectify certain inequities,” the well-armed Goblin puts a plan into action, even though Osborn is unaware of his condition, a la Jeckyll and Hyde.

Ultimately, the hero and villain clash, with innocent New Yorkers caught in the balance.

“Evil Dead” director Sam Raimi does a fine job adapting this previously dormant material into a feature worthy of the ground-breaking character. Very few liberties are taken with the story, and the ones that are (such as Spidey’s webbing ability envisioned as a genetic mutation) seem like improvements.

Raimi (who verified his dramatic knack with the stunning “A Simple Plan”) draws a splendid performance out of Maguire. The actor nails the requisite dopiness of the Parker role and comes across like a realistic, sympathetic individual as the film progresses.

The hyper-kinetic images that Raimi has perfected recall his Three Stooges-meets-“The Shining” approach to horror movies. His oddball vision isn’t as gothic as “Batman” as sober as “X-Men” or as campy as “Superman,” but it appears to mesh with the tone of the long-running comic book series. This is especially apparent when the wall-crawler’s newfound capabilities are explored. From climbing up skyscrapers to shooting out strands of webbing to evincing “spider sense,” Raimi visualizes these attributes with flair.

So why is this movie a cinematic triple and not a home run?

Consider these points:

o Spider-Man is shown spouting comical quips at his enemies. Yet Peter Parker himself is virtually humorless. Putting on a mask doesn’t instantly make you funny … even if it’s a funny mask.

o Danny Elfman’s one-dimensional score sounds indistinguishable from “Batman” and the dozens of other cartoonish orchestrations he has composed. The music doesn’t fit the movie.

o It’s revealed that Peter has lived next door to Mary Jane since they were in grade school, except she doesn’t seem to really know who he is. That’s just sloppy; it isn’t like his super power is invisibility.

o While the “Spider-Man” costume is respectable (Raimi even makes sport of this idea during the film’s funniest sight gag), sometimes the Goblin looks like a goofy Mighty Morphin Power Rangers villain.

o Early on, Peter takes revenge upon the classmates that mistreated him during an extended fight scene in front of dozens of peers. He reveals super strength, agility and precognition. Why even keep a secret identity if you’re going to garishly display your capabilities in front of the whole school?

o There is a moment in the picture where a distraught mother cries, “Save my baby.” ‘Nuff said.

But the one problem that the script (by “Panic Room” scribe David Koepp) can’t quite evade is the sensation that there are two separate ideas being forced into one film. The exposition-dense first hour dedicated to Peter’s back story and Spider-Man’s origin seems completely removed from the Green Goblin conflict. The transition isn’t smooth, resulting in a narrative that feels as cohesive as a Saturday afternoon serial.

It’s fine for a comic book to be episodic. But an anticipated film of this magnitude needs to spin a tale that sticks together.