The present invention relates to a press machine that has a vertically movable ram for supporting upper or lower bending tools, said ram being integrally provided with an operation member, and a position determining member having an adjustable position located at a suitable point on said press machine such that when the operation member on the ram contacts the position determining member, the vertical movement of the ram is stopped. The press machine further includes a screw mechanism that is screw-coupled to the position determining member and is movable in an axial direction, a pulse motor drive unit which turns the threaded bolt, and a manual pulse generator for operating the pulse motor from a remote location.