PURPOSE: To enable efficient filtration by applying two layers of silicon carbide particles having specific average particle diameters to the surface of a base material composed of sintered particles of silicon carbide having specific average diameters to form a filtering film.

CONSTITUTION: Particles of silicon carbide having average diameters of 0.4-0.8 μm are applied to the surface of a base material 1 composed of sintered particles of silicon carbide having average diameters of 0.8-2.0 μm to form an intermediate layer 2 and particles of silicon carbide having average diameters of 0.1-0.3 μm are attached to the surface of said layer 2 to form a filtering film 3. In this manner, the particles forming the filtering film are prevented in advance from getting into between the particles forming the base material so that diameters of pores in the filtering film can be surely maintained at a required set value and also pressure losses in filtration can be restrained and flow rate of water can be kept at appropriate values, thereby enabling efficient filtration.