The present invention relates to a stapler, which can be used even when a user is unable to use his/her hands, is easily usable whatever size the user's hands are, which imparts fixed operation feeling regardless of the operating sites, and by which binding operations is executed with less operations, with a small number of components. The stapler(S)is provided with: a base(1)having a staple bending part(1x); a staple feeding mechanism(2); a space(S)is provided between the staple feeding mechanism and the base; a magazine(21)for containing the staple and making the staple face successively thestaple bending part(1x); a binding operation body(3)which is located opposite to the base over the staple feeding mechanism and receives operation force for pushing out the staple; a guide mechanism(4)for linearly advancing/retreating the binding operation body(3)to the base(1); and a pressing member(5),located on the binding operation body, having a function for pushing out the staple toward thestaple bending part 1x when receives the operation force.