To solve the problem in a conventional electric motor: a zero point correcting operation is required after an assembling step and it takes time and effort in an inspection step before shipment.

In an assembling step of the electric motor 14, a resolver 20 temporarily fixed to a zero point by a temporarily fixing member 44 is incorporated into a motor housing 25, and in this state, a predetermined current is applied to the electric motor 14 to fix an electric angle of the electric motor 14 at a predetermined angle, and the zero point of the electric angle of the electric motor 14 is matched with the zero point of the resolver 20. A resolver stator 46 is fixed using an adhesive A put into an adhesive insertion hole 53, and then the temporarily fixing member 44 is separated from the resolver 20 by a magnetic force of a coupling tool 43 inserted into a coupling tool inserting hole 42, and is attracted to an end member 32 side.