A controller able to efficiently operate an electric motor of an axial air-gap type as an electric motor and an electricity generator is provided.The controller of the electric motor (3) of the axial air-gap type has a rotor (11) having a permanent magnet, and a first stator (12a) and a second stator (12b) oppositely arranged through the rotor (11) in a rotation axis direction of the rotor (11); wherein the controller includes a first electric current command determining section (30) for supplying a driving electric current from a first power source (38a) to an armature winding (13a) of the first stator (12a), and rotating the rotor (11); a first electric current control section (40a); a second electric current command determining section (37) for charging a second power source (39) by electric power generated in an armature winding (13b) of the second stator (12b) when the rotor (11) is rotated by the supply of the driving electric current to the armature winding (13a) of the first stator (12a); and a second electric current control section (40b).