Mandy Moore I Love My Ironed Maiden T-Shirt

2/6/2014 6:00 AM PST

Iron Maiden just got taken to the cleaners by Mandy Moore ... to be neatly sanitized, steamed and pressed.

Apparently big celebs don't toss their dirty, old rock n' roll t-shirts into a washing machine like the rest of us ... because Mandy took her classic Iron Maiden t-shirt to a dry cleaners -- where it was freshly cleaned, ironed and sheathed in plastic.

That just ain't right.

Fun Fact:  Iron Maiden had its biggest success in the early '80s ... right about the time Mandy was born.