A method for manufacturing a bearing mechanism used in an electric motor includes (a) inserting an annular member into a substantially cylindrical closed-bottom cup member to bring a first end portion of a shaft fitted to the annular member into contact with a thermoplastic resin member arranged on an inner bottom surface of the cup member, bringing the annular member into contact with the shaft in a direction leading from an opening of the cup member to a bottom portion of the cup member, and fixing the annular member to the cup member; and (b) deforming the resin member by externally heating the bottom portion of the cup member and applying a load acting toward the bottom portion on a second end portion of the shaft. Further, an electric motor includes a rotor unit, a stator unit, and the bearing mechanism manufactured by this method.