To prevent adjacent wafers from being brought into close contact by making it possible to clean and remove slurries adhered to both ends of the wafers after slicing.

Cleaning medium supply passages 32, 33 are formed in the work supporting apparatus 22 for mounting a work 23 at a wire saw by adhesively supporting. When the work 23 is sliced to many wafers 23a, the passages 32, 33 are opened between the wafers 23a. In this state, the medium is supplied between the wafers 23a via the passages 32, 33 of the apparatus 22 to clean and remove the slurries adhered to both ends faces of the respective wafers 23a.