PURPOSE: A press device is provided to allow a ball and a ball groove coupled with each other through a ball screw to have relative positions which are replaceable in every molding process. CONSTITUTION: A press device comprises a screw shaft(40), a ball screw nut, a lock unit(130), a slider moving unit(120), a second motor, and a position detector(151). The screw shaft is mounted on a rotating shaft of a first motor(35), and drives a slider(50) with respect to a base(10) by the rotation of the first motor. The ball screw nut is screw-coupled to a ball screw portion mounted on the screw shaft. The lock unit integrates the screw shaft and a support plate(30). The slider moving unit rotates the ball screw nut in forward and reverse directions with respect to the screw shaft by the rotation torque input from an input shaft. The second motor provides rotation torque to the slider moving unit through the input shaft. The position detector is arranged with respect to the first motor and the second motor, and detects position of the slider.