A blower apparatus in which power supply voltage (Vb) of a battery is supplied through a power supply switch of which on-off control is made according to a state of an ignition switch of a vehicle, comprising: a motor having a stator with a coil wound therearound and a rotor disposed rotatably about a rotation shaft; a blowing fan on the rotation shaft; a motor drive circuit for electrically driving the coil; a microprocessor for controlling the motor drive circuit; a motor case integrally containing the motor, the motor drive circuit, and the microprocessor; a first power supply input terminal to which the power supply voltage (Vb) of the battery is supplied through the power supply switch; a second power supply input terminal to which the power supply voltage (Vb) of the battery is directly supplied from the battery; an internal power line for supplying power supply voltage (Vig) applied to the first power supply input terminal to the motor drive circuit and the microprocessor in the motor case; a smoothing capacitor connected to the internal power line; characterized by: a cut off control circuit for cutting off supply of the power supply voltage (Vb) to the internal power line according to a command from the microprocessor, wherein the blower apparatus further comprising: a first resistor set between the first power supply input terminal and the internal power line, wherein the first resistor limits an inrush current from the first power supply input terminal, wherein the cut off control circuit has a switch element set between the second power supply input terminal and the internal power line, and makes the switch element turn off to cut off supply of the power supply voltage (Vb) to the internal power line. a motor having a stator with a coil wound therearound and a rotor disposed rotatably about a rotation shaft; a blowing fan on the rotation shaft; a motor drive circuit for electrically driving the coil; a microprocessor for controlling the motor drive circuit; a motor case integrally containing the motor, the motor drive circuit, and the microprocessor; a first power supply input terminal to which the power supply voltage (Vb) of the battery is supplied through the power supply switch; a second power supply input terminal to which the power supply voltage (Vb) of the battery is directly supplied from the battery; an internal power line for supplying power supply voltage (Vig) applied to the first power supply input terminal to the motor drive circuit and the microprocessor in the motor case; a smoothing capacitor connected to the internal power line; characterized by: a cut off control circuit for cutting off supply of the power supply voltage (Vb) to the internal power line according to a command from the microprocessor, wherein the blower apparatus further comprising: a first resistor set between the first power supply input terminal and the internal power line, wherein the first resistor limits an inrush current from the first power supply input terminal, wherein the cut off control circuit has a switch element set between the second power supply input terminal and the internal power line, and makes the switch element turn off to cut off supply of the power supply voltage (Vb) to the internal power line. a cut off control circuit for cutting off supply of the power supply voltage (Vb) to the internal power line according to a command from the microprocessor, wherein the blower apparatus further comprising: a first resistor set between the first power supply input terminal and the internal power line, wherein the first resistor limits an inrush current from the first power supply input terminal, wherein the cut off control circuit has a switch element set between the second power supply input terminal and the internal power line, and makes the switch element turn off to cut off supply of the power supply voltage (Vb) to the internal power line. a first resistor set between the first power supply input terminal and the internal power line, wherein the first resistor limits an inrush current from the first power supply input terminal, wherein the cut off control circuit has a switch element set between the second power supply input terminal and the internal power line, and makes the switch element turn off to cut off supply of the power supply voltage (Vb) to the internal power line.