A porous polyester film having an apparent specific gravity of not more than 1.3, which comprises a polyester film having many voids (layer (A)) comprising a polyester and a thermoplastic resin incompatible with said polyester, and a polyester film having many fine voids (layer (B)) comprising a polyester and inorganic fine particles having an average particle size of not more than 1 .mu.m, the two layers being bonded to each other, wherein the layer (B) has a porosity of not less than 20% by volume, and a thickness of 1-20 .mu.m that is not more than 30% of the thickness of the porous film. Due to the present invention, a porous polyester film capable of providing an image-receiving sheet superior in surface smoothness, image density, and resistance to wrinkles can be provided.