A solid-state imaging device according to an embodiment includes: an imaging element including a plurality of pixel blocks each containing a plurality of pixels; a first optical system forming an image of an object on an imaging plane; and a second optical system including a microlens array, the microlens array including a light transmissive substrate, a plurality of first microlenses formed on the light transmissive substrate, and a plurality of second microlenses formed around the first microlenses, a focal length of the first microlenses being substantially equal to a focal length of the second microlenses, an area of the first microlenses in contact with the light transmissive substrate being larger than an area of the second microlenses in contact with the light transmissive substrate, the second optical system being configured to reduce and reconstruct the image formed on the imaging plane on the pixel blocks via the microlens array.