A piston for an engine is provided, that makes it possible to improve supply of engine oil to a recessed part thereof. The piston includes a resin coating film and a recessed part on a surface of a skirt part. In the piston, resin coating films are distributed in a patchy fashion on the surface of the skirt part. The recessed part is formed by the surface of the skirt part, between adjacent surfaces of the patchy resin coating films and by the adjacent resin coating films, forming a net-like groove. An outer-edge resin coating film, extending in a piston movement direction, is provided at the ends, in a piston circumferential direction of the skirt part.