To realize shortening of a manufacturing process, improvement of workability, and reduction of a manufacturing cost by a method therein a gap between a pipe and an end face member is sealed by utilizing a nature to shrink resin during molding of a resin molding product.

In a canned motor wherein a pipe 12 is molded by using thermoset resin and integral molding with a mold flange 11 situated on the end face side of the pipe 12 is carried out, the canned motor comprises a contact surface pressed in the longitudinal direction of the pipe 12 through contraction force of resin exerted on a protrusion part; and an O-ring 30 to generate an elastic force by a press force exerted on the contact surface and seal a gap between the mold flange 11 and the end face of the pipe 12.