PROBLEM TO BE SOLVED: To obtain heating and high heating efficiency while preventing the enlargement of a device by performing heating with a low frequency microwave in a single mode.SOLUTION: A microwave heating device 1 performs heat sterilization by being heated to 100°C or higher by irradiating the hermetically packaged food PF with microwaves. The microwave heating device 1 includes: a microwave irradiation part 40 which irradiates the packaged food PF with 2450 MHz microwaves in a multi-mode； and a microwave irradiation part 50 which irradiates the packaged food PF with 915 MHz microwaves in a waveguide 53 in a single-mode.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】低周波数側のマイクロ波による加熱をシングルモードで行うことで、装置の大型化を防止しつつ、均一加熱と高い加熱効率を得る。【解決手段】マイクロ波加熱装置１は、密封包装された包装食品ＰＦにマイクロ波を照射して１００℃以上にして加熱殺菌を行う。マイクロ波加熱装置１は、２４５０ＭＨｚのマイクロ波をマルチモードで包装食品ＰＦに照射するマイクロ波照射部４０と、９１５ＭＨｚのマイクロ波を導波管５３内にてシングルモードで包装食品ＰＦに照射するマイクロ波照射部５０とを備えている。【選択図】図１
