A motor driving device includes: a rectifier that rectifies an AC current and outputs a DC current to a DC link; an inverter unit that converts the DC current to an AC current for a motor; an initial charging unit that initially charges a smoothing capacitor with the DC current that flows through a charging resistor; a storage unit that stores a load capability of the charging resistor; a power calculation unit that calculates an amount of power generated in the charging resistor in response to the DC current flowing therethrough; and an opening/closing unit that shuts off the DC current from flowing in the smoothing capacitor when the amount of power reaches the load capability during an initial charging period and allows the DC current to flow in the smoothing capacitor after the shutoff when the amount of power is smaller than or equal to a threshold value.