An opening/closing mechanism includes a first inclined portion disposed in an opening/closing body that opens/closes while a first shaft serves as a fulcrum in a main body, a second inclined portion disposed in the opening/closing body, and a swing portion that swings between the first inclined portion and the second inclined portion while a second shaft disposed in the main body serves as a fulcrum, in which during a closing operation of the opening/closing body, the swing portion applies a force in a closing direction of the opening/closing body by coming into contact with the first inclined portion, after applying a force in an opening direction of the opening/closing body by coming into contact with the second inclined portion.