PURPOSE: To manufacture simply a T- or Y-shaped filter at low cost by uniting a pair of T- or Y-shaped half bodies, formed by press-molding a metallic plate, to a body by welding to form the main body of the filter.

CONSTITUTION: A half body 4 is formed by press-molding a metallic plate of steel, stainless, etc. with a metallic mold having a specified form. A pair of bisymmetrical half bodies 4 and 4 are welded at the contact surfaces 5 and 5 to form a Y-shaped main body of a strainer 1 (main body of filter). The T-shaped strainer can be manufactured in the same way as the Y-shaped strainer. In this way, the T- or the Y-shaped filter with a smooth internal flow can be simply manufactured at low cost.