An opening and closing mechanism includes a movable member removably mounted relative to a main body of an apparatus, an opening and closing member having a cover portion, protrusions, and pivot shafts, and shaft position adjusters to change positions of the pivot shafts while the cover portion pivots between a closed position and an open position. The opening and closing member is arranged so that, on an imaginary plane perpendicular to a central axis of each pivot shaft on which each pivot shaft and the movable member are projected, a projected portion of each pivot shaft is positioned to interfere with a projected portion of the movable member when the cover portion is placed at the closed position, and the cover portion is positioned so as not to interfere with a trajectory of movement of the movable member while the cover portion pivots toward the open position.