Abstract: In a canned motor including a stator with a cylindrical housing, a stator core having a stator winding and mounted on an inner surface of the motor housing, a pair of end brackets each secured to one of two opposite open ends of the motor housing, a cylindrical can mounted on an inner side of the stator core and secured at opposite ends to the end brackets, and a rotor arranged on an inner side of the can, the stator sealed by the can is filled with a porous insulator. The canned motor having the stator provided with the porous insulator is produced by a method wherein a mixture of filler in particulate form and resin in powder form is poured in a space in the stator sealed by the can, and the mixture is heated to allow the resin to cure to form the filler and resin into a porous body, to achieve molding of the stator and provide it with an insulator in the form of the porous body.