To provide an electric motor drive controller which can rapidly discharge the charge of a capacitor, even at the fault generation of an electric motor.

The electric motor drive controller includes the electric motor 27; a motor drive circuit for driving the motor 27; a capacitor 29 connected in parallel with the motor drive circuit; and an SMR 22 for controlling the supply of a power to the electric motor drive circuit. The electric motor drive circuit has an inverter 26 for supplying ac power to the electric motor 27, and a step-up/step-down converter 25 for receiving a dc voltage to step up or step down the voltage and supplying to the inverter 26. When the supply of the power to the electric motor drive circuit is interrupted by the SMR 22, the charge stored in the capacitor 29 is discharged by the step-up/step-down converter 25.