To provide a controller for steering apparatus capable of reducing load on main power supply by utilizing auxiliary power supply effectively.

This controller for steering apparatus includes a the main power supply 4 for supplying electric power to a motor 1m of the steering apparatus 1s of a vehicle, the auxiliary power supply 9 for supplying electric power to the motor 1m, and a control circuit 15 for controlling supply of electric power to the motor 1m by the auxiliary power supply 9 based on an electric power value set as a charging and discharging threshold value. The control circuit 15 is constituted to monitor electric power consumption of the motor when parking the vehicle and change the charging and discharging threshold value based on the electric power consumption of the motor.