A recording medium conveying apparatus includes: a mount member having an outer peripheral surface on which a recording medium is placed; a ventilation member provided along part of an inner peripheral surface of the mount member; an air chamber having air permeability to/from the outer peripheral surface side of the mount member through the holes provided in the mount member and the ventilation member; a suction unit; and a side wall member having side wall surfaces covering part of side surfaces of the ventilation member. A buffer region that is not provided with the ventilation member is included in a ventilation member-disposed region enclosed by straight lines passing through the first surface, the second surface, and the pair of side wall surfaces, in an arbitrary cross section that intersects the pair of side wall surfaces across the ventilation member and is perpendicular to the first surface.