In a microwave heating device, a microwave from oscillation units (1a, 1b) is divided into a plurality of parts by power distribution units (2a, 2b) and inputted to amplification units (4a, 4b, 4c, 4d). A desired microwave power from the amplification units is supplied to a heating chamber (8) from feed units (5a, 5b, 5c, 5d). A reflection power reflected from the heating chamber via the feed units to the amplification units are detected by power detection units (6a, 6b, 6c, 6d). The feed units have a plurality of antennas having different characteristics of the microwave supplied to the heating chamber. The microwave heating device includes a control unit (7) which extracts an oscillation frequency at which the reflection power detected by the power detection units is minimum and oscillates the oscillation unit by the extracted oscillation frequency so that microwaves of different characteristics are supplied to a heating chamber from the antennas.