Abstract: Provided is a microwave processing apparatus that can irradiate an object with microwaves more uniformly. A microwave processing apparatus 1 includes a cavity that has a cylinder-like shape, and includes an internal space for accommodating an object, the cavity being provided with a microwave passage area in a partial region in an axial direction; a microwave generator; a rotary member that is provided on an outer circumferential side of the cavity so as to be rotatable, and includes, on an outer circumferential side of the microwave passage area, a cylinder-like member having a plurality of areas through which microwaves can pass; and a cover member that is provided while covering the entire cylinder-like member in a circumferential direction, and forms, on an outer circumferential side of the cylinder-like member, a wave guidepath for the microwaves introduced from the microwave generator.