He apologized to other women who have accused him of sexual misconduct, saying he was "tremendously sorry" and that he needed to be "careful and more sensitive" to make sure it doesn't happen again.
The Minnesota Democrat said he was going back to work and wanted to regain people's trust, and that he had to "learn from my mistakes."
Three women have alleged that Franken grabbed their buttocks while they posed for photos with him.
Broadcaster and model Leeann Tweeden was the first to publicly accuse the former "SNL" funnyman of sexual misconduct.
She charged earlier this month that Franken forcibly kissed her during a rehearsal for a skit and that he groped her breasts during a 2006 USO tour.
She produced a photo showing her asleep while he placed his hands on her breasts over the Kevlar vest she was wearing.
Comment: How does someone need to learn that it's not appropriate to grope a sleeping woman's breasts? Did Al Franken just recently become a human being and doesn't understand human behavior? No, he knew what he was doing was wrong but didn't care. Anything he says now is just PR to try and repair his image. He needs to leave public service and never come back.