An inverter device includes an inverter circuit, which has switching elements in a bridge connection, a capacitor, which is connected in parallel to the input side of the inverter circuit, a temperature detector, which detects the temperature of the capacitor, a battery charge information acquisition section, which acquires charge information related to a battery connected to the input side of the inverter circuit, and a warm-up controller. When the temperature of the capacitor detected by the temperature detector is lower than a prescribed temperature, the warm-up controller determines a warm-up current based on the battery charge information acquired by the battery charge information acquisition section and the temperature of the capacitor detected by the temperature detector, and controls the switching elements of the inverter circuit to supply the warm-up current to the coil of an electric motor connected to the output side of the inverter circuit.