An inverting apparatus and a control method thereof are provided. The inverting apparatus includes an inverting circuit, a detection circuit, and a control circuit. The inverting circuit converts a DC input power into an AC output power. The detection circuit detects an input voltage and an input current. The control circuit provides a control signal for disturbing the input voltage, such that a voltage value of the input voltage is adjusted to a command voltage represented by the control signal. The control circuit calculates an input power corresponding to each of time points, calculates a power variation between the disturbed power and the undisturbed power, then determines whether the power variation is larger than a predetermined variation, and sets a disturbance voltage according to the determination result, based on an MPPT operation or based on a disturbance direction of the command voltage of the previous time point.