PURPOSE: To simply form a wafer arrangement, on a boat, which corresponds to a diffusion treatment by a method wherein wafer water arrangement on the heat is input to an input device, a wafer arrangement data is formed, this data is stored in a first storage device, this data is made to correspond to each diffusion furnace tube and the data is stored in a second storage device.

CONSTITUTION: The following are provided: a data input device 24 to which a wafer arrangement of wafers 1 on a boat 49 is input; a processing means 20 which forms a data of the wafer arrangement which has been input by the data input device 24; a first storage device 28 where the wafer arrangement data formed by means of the processing means 20 is stored; a second storage device 29 where the wafer arrangement data stored in the first storage device 28 is stored so as to correspond to individual diffusion furnace tubes 54a to 54d; a device which transfers wafer waters 1 to a prescribed position between a cassette 2 and the boat 49 on the basis of a wafer arrangement pattern which has been stored in the second storage device 29. Thereby, since the wafer 1 can be set in all groove positions of the boat 49 in arbitrary positions, directions and number of various kind of wafer 1, it is possible to correspond to various types of processes.