A microwave processing apparatus is provided with an oscillator, a power amplifier, a heating chamber that accommodates an object to be heated, a power feeder which is disposed on a wall surface of the heating chamber, which receives an output transmitted from a microwave generator and which radiatively feeds the microwave into the heating chamber, and a power detector that detects the power reflected from the power feeder to the power amplifier. The microwave processing apparatus determines a plurality of points of heating frequencies by using top several points of minimum point frequencies of the reflected power, and performs frequency hopping heating within a predetermined unit time.