PURPOSE: To automatically set a strainer to a strainer fitting part by releasing the strainer with a holding mechanism when the holding mechanism positions above the strainer fitting part with shifting mechanism.

CONSTITUTION: The shifting mechanism 4 shifts the holding mechanism 2 to a position laying a strainer S by rotating a base part 4a and also the holding mechanism 2 is descended toward the strainer S, and by closing one pair of holding pieces 2a, 2b, the strainer S is held. By ascending the holding mechanism 2, the shifting mechanism 4 is worked so as to position the strainer fitting part 1. Successively, the holding mechanism 2 is descended until an inclining low end part of the strainer S contacts on the strainer fitting part 1, and at the time of contacting this part, one pair of the holding pieces 2a, 2b are opened. By this method, the inclining upper end part of the strainer S, is also dropped in the fitting part 1 to complete the setting of the strainer S.