In a microwave heating device of the present invention, a heating-chamber input portion is adapted to direct, to a heating chamber, microwaves having propagated through a waveguide tube and having passed through the positions where microwave radiating portions are formed, thereby realizing a state where progressive waves are dominant among the microwaves propagating through the waveguide tube, so that the microwave radiating portions are caused to radiate, to the inside of the heating chamber, microwaves based on the progressive waves propagating through the waveguide tube. This enables uniformly heating an object to be heated, without using a rotational mechanism.