Image forming apparatus and sheet storing apparatus

An image forming apparatus includes a cassette, an image forming unit configured to form an image on a sheet fed from the cassette a set position, a guide rail configured to draw out the cassette from the set position, and a movable stopper unit that regulates a movement of the cassette in a draw-out direction by abutting with the cassette while the cassette is drawn out from the set position along the guide rail. The movable stopper unit includes a regulating portion movable between a regulating position where the regulating portion regulates a movement of the cassette within a moving trajectory of the cassette in moving in the draw-out direction and a retracting position where the regulating portion is located outside of the moving trajectory and does not regulate the movement of the cassette, and an urging portion configured to urge the regulating portion to the regulating position.