A solid-state imaging device according to an embodiment includes: a first optical system configured to form an image of an object on an image formation plane; an imaging element comprising an imaging area which includes a plurality of pixel blocks each including a plurality of pixels; a second optical system configured to include a microlens array including a plurality of microlenses provided to correspond to the plurality of pixel blocks and reduce and re-form an image scheduled to be formed on the image formation plane, in a pixel block corresponding to an individual microlens; and a signal processing unit configured to perform image signal processing with an optical position relation between each microlens and the pixel block corrected, by using an image signal of the object obtained by the imaging element.