The mid-’70s are a period remembered for the gas shortage, disco, jiggle TV shows.

Many of today’s thirtysomething boomers look back fondly at this era when they came of age.

This is also the time of Eric Foreman, the main character of “That ’70s Show,” which airs at 8:30 p.m. Sundays on Fox (it debuted last Sunday).

This retrocomedy, set in the era of bell bottoms, smile buttons and 8-tracks, is a flashback to the “Me Decade” created by the team of Bonnie and Terry Turner and Mark Brazil (“Third Rock From the Sun”). Hammocked between “The Simpsons” and “The X-Files,” the series is being given every chance by Fox.

“That ’70s Show” focuses on Eric (played by Topher Grace) and his group of friends, all played by relative TV newcomers, who hang out in the basement of Eric’s suburban Wisconsin home.

One ongoing plotline is the tentative romance forming between Eric and the girl next door, Donna, played by Laura Prepon. They’ve been best friends forever, but now their relationship is evolving.

So far, the storylines have been sitcom standards which have stood intact since the ’50s. Eric and friends take the Vista Cruiser to a Todd Rundgren concert against his father’s wishes. Eric’s mother throws him a surprise 17th birthday party, which he doesn’t want.

It’s the new twists the writers supply that make “That ’70s Show” stand out. In a scene that caused some outcry earlier this summer, Eric and three friends smoke pot in the basement. Then, his parents call him upstairs and talk to him about the car, while the wall in the background dances about.

Each episode has featured a fantasy scene or two. Eric’s mother frets about what the teens are up to at his birthday party (she pictures them in “Superfly” garb, refusing to use coasters and making long-distance phone calls). Eric dreams about his first romantic encounter with Donna, only to be woken up by breakfast in bed from his family.

Eric is the ultimate straight man in each show. He’s surrounded by his oddball friends, the dim Kelso, Kelso’s narcissistic girlfriend, Jackie, the conspiracy-minded Hyde, the sarcastic Donna and Fez, the foreign-exchange student from an indeterminate country. Wackiest of all are his parents, Red and Kitty, played with gusto by veteran character actors Kurtwood Smith and Debra Jo Rupp. In an ironic note, Tanya Roberts, the last of “Charlie’s Angels,” actually plays Donna’s sexy mother in this show.

What “That ’70s Show” offers, beyond inspired bits of comedy, is a look back to a simpler time, when Peter Frampton was a musical god and when women could live in a town called Hooterville without a P.C. firestorm. Its nostalgia value is what puts “That ’70s Show” over the top.