A motor having a structure configured to reduce magnetic resistance between a rotor and a stator, a method for manufacturing the motor, and a washing machine using the motor are disclosed. The motor includes a rotor, and a stator co-operating with the rotor. The stator includes a main core and an auxiliary core. The main core includes a base and a plurality of teeth protruding from the base. The auxiliary core is structured to prevent the occurrence of magnetic resistance from being generated from spaces, defined between adjacent teeth, when the stator co-operates with the rotor.