A motor controller, including: a power supply which supplies DC power; an inverter which converts the DC power into AC power to be supplied to a motor; a shunt resistor which connects the power supply and the inverter; and a controller which supplies a control signal to the inverter to drive the motor and determines an error of the inverter when it is determined that a size of voltage between both ends of the shunt resistor is less than a predetermined first reference value. Thus, a motor controller is provided which detects an error of an inverter more easily and precisely, and a control method thereof and an error detecting apparatus of an inverter.