Abstract: A binder comprises an operating member supported on a base, a pressing member movable toward and away from the base by the movement of the operating member, and locking means for locking the operating member when the pressing member is set in a binding position. The operating member has a first operating spot and a second operating spot, and the operating member is locked to hold the pressing member at the binding position when the first operating spot is pressed toward the surface of the base, and unlocked to move the pressing member away from the base when the second operating spot is operated similarly.