To use a device as a loading device or unloading device for a load-carrying platform of a truck, move load successively as an alternative of a belt conveyer and a crane or the like, convey load efficiently by using reciprocating movement of a slide plate, with a simple configuration, at low cost and safety sufficiently enough for the small number of people to work.

A slide plate 12 for reciprocating movement is placed on a bottom plate 11 and a moving partition 19 is placed on the slide plate 12, for moving in sync with the slide plate 12 to a direction, for example, forward direction but allowing only the plate 12 to move in a backward direction, of the reciprocating movement of the plate 12, and a fixed partition 20 for fixing the plate 12 irrespectively of the reciprocating movement of the slide plate 12, and the moving partition 19 is transferred to a front position of the plate 12 sequentially and the load A is moved to the forward direction using this partition 19 and pressed by the partition 19 and partition 20.