When a paper feed cassette is again mounted, a pressing portion of a pressing member is brought into contact from the front side on a second surface of an extending portion of a contacting member, and the contacting member is pressed by the pressing member to be displaced from the retract position to the contact position. At this time, the pressing portion of the contacting member presses a pressed portion of a disc member to rotate a third cam itself in the counterclockwise direction in the drawing. Accordingly, the lift lever locked by the third cam is released, and an end portion of an arm member is allowed to move upward.