PURPOSE: To prevent the accumulation of filth on the inner wall of a filth transport pipe by providing a member having a porous surface on a part, the whole, or the entire periphery of the inner wall of the pipe, and impregnating the member with microbes and enzyme to form the pipe.

CONSTITUTION: The member having a porous surface is provided on a part, the whole, or the entire periphery of the inner wall of a pipe, and the member is impregnated with microbes and/or enzyme to form a filth transport pipe. Concretely, a nonwoven fabric 2 impregnated with 10g/m2 enzyme and microbes is provided on the inner wall of the filth transport pipe 1. A steel pipe, a clay pipe, etc., are used as the transport pipe, and proteolytic enzyme or the microbes capable of decomposing org. matter such as starch, saccharides, fat, and oil are used as the microbes and enzyme for impregnating the transport pipe.