PURPOSE: To furnish electric circuit equipment for an electric vehicle which causes little power loss and which is operated simply and can suppress the heating, power loss and shortening of the lifetime of a battery in regenerative braking.

CONSTITUTION: A motor generator 11 for running generates a running torque and regenerates braking energy through transfer of a power to and from a high-voltage storage means 12. A low-voltage storage means 61 feeds electricity to a vehicle-borne electric load 62 having a rated voltage being lower than the voltage of the high-voltage storage means 12. A DC voltage conversion part 2 executes voltage conversion of the power of the high-voltage storage means12 and supplies it to the low-voltage storage means 61. A control part 7 detects lowering of a terminal voltage of the low-voltage storage means 61, gives an instruction for operation to the DC voltage conversion part 2 when the amount of charging of the low-voltage storage means 61 becomes an allowable level or below, according to the degree of lowering of the terminal voltage, and charges the low-voltage storage means 61 to a necessary level. By making the DC voltage conversion part 2 be a rotary type DC-DC converter, a recovery power generated in a high-voltage circuit part for running in regenerative braking can be stored temporarily as inertial energy (rotational energy).