PURPOSE: To supply cylindrical cap-shape parts one by one successively to a part working machine without damage due to mutual collision between the parts.

CONSTITUTION: In a part housing box 10 whose front face is opened to form a part inlet/outlet port 12 and in whose rear face a part push-out window 14 is provided, parts 18 are arranged lengthwise and breadthwise for housing on an inside shelf board 16. While the part housing box 10 is placed on an elevating arm 34 and elevated, a part push-out plate 38 is advanced through the part push-out window 14 in the rear face of the part housing box 10 placed on the elevating arm 34 so as to push out the parts 18 arranged on the shelf board 16 onto a part conveyor 42. Accordingly, parts can be supplied one by one successively to a part working machine without requiring an excessive device such as a tray draw-out device and a tray draw-out base and without damage to the parts due to mutual collision between the parts.