PURPOSE: To stabilize and automate the processing of a material feeder for vacuum processor, by arranging a thin belt between a feeding chamber partitionable through a gate valve while incorporating a lifter laminated with tray, a takeout chamber and a processing chamber.

CONSTITUTION: It is moved such that a tray 16 is held by the clicks 30, 31 of thin belt 23 at the uppermost tray position of lifter 15 arranged in feeding chamber 17 thus to drive a motor 18 and to lift the receiving board 22 by single step through a pole screw 21 to hold the tray 16 with the clicks 30, 31. Then the tray 16 is moved through a motor 42 in the takeout chamber 34 to the processing chamber 26 and processed thereafter moved to the upstage of lifter 32 in the takeout chamber 34 and taken out. Under normal operation, the gate valves 25, 33 are opened to maintain respective chamber 16, 26, 34 under vacuum while when supplying a tray, said valves are closed to block communication. With such arrangement, the stability and the continuity of processing can be improved.