To obtain an imaging device capable of achieving high functionality of the imaging device by facilitating detection of an incident angle of light transmitted through a grating substrate. There is provided an imaging device which includes an image sensor that converts an optical image captured by a plurality of pixels arranged in an array on an imaging surface into an image signal and outputs the image signal, a modulator that is provided on a light receiving surface of the image sensor and modulates light intensity, an image storing unit that temporarily stores the image signal output from the image sensor, and a signal processing unit that performs image processing of the image signal output from the image storing unit, and in which the modulator has a first grating pattern composed of a plurality of concentric circles, and the signal processing unit modulates the image signal output from the image storing unit with a virtual second grating pattern composed of a plurality of concentric circles so as to generate a moiré fringe image and changes a size of the concentric circle of the second grating pattern according to a focus position.