A motor driving device comprising: a rectifier to rectify input AC power; a boost converter to boost power rectified by the rectifier; a capacitor (c) to store a pulsating voltage from the boost converter; an inverter comprising a plurality of switching elements, the inverter transforming AC power, using a voltage across the capacitor, and outputting the transformed power to a motor; a regenerative power consuming unit arranged between the capacitor and the inverter, to consume regenerative power from the motor; an inverter controller to control the inverter a voltage detector to detect the voltage across the capacitor; and an over-voltage sensing unit to sense whether the detected voltage is equal to or higher than the predetermined voltage; and a switching driving unit to output a switching control signal to a switching element (Sbc) in the regenerative power consuming unit while outputting an operation control signal to the inverter controller when the voltage across the capacitor is equal to or higher than a predetermined voltage, characterised in that the over-voltage sensing unit comprises: a plurality of resistors (R1, R2, R3); and an operational amplifier to, at one input terminal of the operational amplifier, receive DC link voltage (Vdc) detected by the voltage detector, wherein the other input terminal of the operational amplifier is connected to the resistors (R1, R2, R3), wherein a reference value is determined in accordance with a resistance distribution ratio among the resistors (R1, R2, R3), and the operational amplifier compares the DC link voltage (Vdc) with the reference value corresponding to the predetermined voltage, wherein when DC link voltage (Vdc) is equal to or higher than the predetermined voltage, the operational amplifier outputs a signal having a first level, and wherein when DC link voltage (Vdc) is not equal to or higher than the predetermined voltage, the operational amplifier outputs a signal having a second level. a rectifier to rectify input AC power; a boost converter to boost power rectified by the rectifier; a capacitor (c) to store a pulsating voltage from the boost converter; an inverter comprising a plurality of switching elements, the inverter transforming AC power, using a voltage across the capacitor, and outputting the transformed power to a motor; a regenerative power consuming unit arranged between the capacitor and the inverter, to consume regenerative power from the motor; an inverter controller to control the inverter a voltage detector to detect the voltage across the capacitor; and an over-voltage sensing unit to sense whether the detected voltage is equal to or higher than the predetermined voltage; and a switching driving unit to output a switching control signal to a switching element (Sbc) in the regenerative power consuming unit while outputting an operation control signal to the inverter controller when the voltage across the capacitor is equal to or higher than a predetermined voltage, characterised in that the over-voltage sensing unit comprises: a plurality of resistors (R1, R2, R3); and an operational amplifier to, at one input terminal of the operational amplifier, receive DC link voltage (Vdc) detected by the voltage detector, wherein the other input terminal of the operational amplifier is connected to the resistors (R1, R2, R3), wherein a reference value is determined in accordance with a resistance distribution ratio among the resistors (R1, R2, R3), and the operational amplifier compares the DC link voltage (Vdc) with the reference value corresponding to the predetermined voltage, wherein when DC link voltage (Vdc) is equal to or higher than the predetermined voltage, the operational amplifier outputs a signal having a first level, and wherein when DC link voltage (Vdc) is not equal to or higher than the predetermined voltage, the operational amplifier outputs a signal having a second level. a plurality of resistors (R1, R2, R3); and an operational amplifier to, at one input terminal of the operational amplifier, receive DC link voltage (Vdc) detected by the voltage detector, wherein the other input terminal of the operational amplifier is connected to the resistors (R1, R2, R3), wherein a reference value is determined in accordance with a resistance distribution ratio among the resistors (R1, R2, R3), and the operational amplifier compares the DC link voltage (Vdc) with the reference value corresponding to the predetermined voltage, wherein when DC link voltage (Vdc) is equal to or higher than the predetermined voltage, the operational amplifier outputs a signal having a first level, and wherein when DC link voltage (Vdc) is not equal to or higher than the predetermined voltage, the operational amplifier outputs a signal having a second level.