An imaging apparatus includes, a diffraction grating that diffracts an electromagnetic wave emitted from an electromagnetic wave source, a shield grating including a shield portion that prevents transmission of the electromagnetic wave and a plurality of transmission portions that allows the electromagnetic wave to transmit therethrough, and a detector that detects the electromagnetic wave transmitted through the transmission portions of the shield grating. The diffraction grating forms an interference pattern in a grid pattern by diffracting the electromagnetic wave; the shield grating has the plurality of transmission portions arranged two-dimensionally; and a ratio of an area of the transmission portion to the area of a unit pattern composed of a portion of the shield portion and one transmission portion of the plurality of transmission portions is larger than 0.25.