To provide a control device of an electric motor which improves the reliability of smooth actuation of the electric motor with a simple structure, and to provide a vehicle steering gear including the control device of the electric motor.

A control device 21 provided between a motor housing 16 and a gear housing 17 includes: a base 22 fixed to the gear housing 17 and to which a circuit board 23 is fixed; and a connector module 24 for connecting the circuit board 23 with a power source B. The connector module 24 includes a bus bar 31 connecting the circuit board 23 with the power source B and a module holder 32 holding the bus bar 31. The module holder 32 is formed into a square box shape covering the circuit board 23 from the motor housing 16 side.