A medium drive unit includes a frame having an operating section, on a rear surface of which facing the main body side of the frame is provided a projection projecting toward the button, and which, upon receiving a depression operation from an outer surface side facing the outside, is biased toward the main body side and pushes the button with the leading end of the projection, a frame main body which surrounds the operating section so as to be separated from the operating section by an opening which extends surrounding the operating section, and passes through the front and rear surfaces of the frame, and an elastic support piece which extends through the opening along an edge of the operating section adjacent to the opening, of which one end is connected to the frame main body and the other end to the operating section.