PURPOSE: To easily perform the operation at the movement with a large stroke by providing a base part consisting of a plurality of members, and dividing the female screw part of a through-hole so that the screwing between the base part and a feed screw part is released.

CONSTITUTION: In general feeding work of workpiece, a lower base part 23 is connected to an upper base part 24 so that a feed screw part is screwed to a female screw part 22, and the locking groove part of a locking member 26 is hooked by the locking piece 39 of the upper base part 24 to form the state where the lower base part 23 is never separated from the upper base part 24. When the feed screw part is moved with a large stroke in a work such as replacement of workpiece, the locking groove part of the locking member 26 is released from the locking piece 39 of the upper base part 24, and the lower base part 23 is rotated and separated from the upper base part 24 to form the state where the upper screw part 22b of the feed screw part is removed. The feed screw part released from the screwing is easily removed from the base part, and moved with the large stroke.