To simplify the extension of piping in the chamber of a vacuum drying processing apparatus and the structure of the apparatus.

The vacuum drying apparatus includes a vacuum chamber room A that accommodates one or a plurality of substrates p that separates the atmosphere by a separation wall 1 to maintain a sealed state, a mobile of fixed heating plate C that is equipped in the chamber room A and on which the accommodated one or a plurality of substrates p is installed, and a pressure chamber B separated from the atmosphere by a separation wall 21 and the sealed state can be maintained. The vacuum chamber room A and the pressure chamber B are partitioned by sealed shutters 25 that are adjacent with each other at a near position and open and hold a communication state by the opening operation of the sealed shutter and a sealed state by the closing operation can be maintained which are independent from each other. The vacuum drying of the substrate p in the vacuum chamber room A can be performed by closing the sealed shutter 25. By opening the shutter, atmospheric pressure can be returned to the vacuum chamber room A.