An imaging device according to the present invention comprises a lens unit having a frame to which a lens is attached, an image sensor which ray of light that has passed the lens should enter, and a board member fixed to the frame of the lens unit, the board member being provided with an aperture for accommodating the image sensor, and the image sensor being adhered and fixed to the board member. Here, a protrusion which extends along an edge of the aperture is formed on a lens-side surface or a rear surface of the board member in at least a part of an area surrounding the aperture, and an adhesive is filled between the protrusion and the image sensor to fix the image sensor to the board member.