An apparatus for controlling a compressor is provided. When grounding the apparatus for controlling a compressor, an analogue circuit ground and a digital circuit ground may be insulated from each other to protect the apparatus. A ground of an analogue circuit driven by commercial alternating current (AC) power, and a ground of a digital circuit driven by a voltage which has been converted from commercial AC power, may also be insulated from each other by a simple circuit device to protect a controller inside the digital circuit.