To use a seal on which a maker's name or the display of a product, a character in accordance with a consumer's preference, or the like is printed and which is stuck on bathroom shoes for increasing the commercial value of the shoes or for the sales promotion of the shoes.

The seal of paper, a plastic film, woody plate, or the like on which a logotype, etc., are printed is stuck on a surface closely contacting the shoe main sheet of a sole 2 and inserted into a mold for blow molding. A parison of a molten resin is mounted on the surface with the seal, and the mold is closed. By introducing compressed air into the parison, the seal is sealed between the sole 2 and the shoe main body 4.