A solid state imaging device includes a package substrate and a solid state imaging element on the package substrate. The package substrate has a mounting plane on which the solid state imaging element is mounted. The package substrate has two reference planes having the same height as the mounting plane, the reference planes projecting in two opposite directions from the mounting plane. The reference planes respectively have at least one pair of positioning reference holes formed therein, such that the centers of the respective pairs of holes are away from the center of an imaging plane of the solid state imaging element by the same distance. The imaging device is produced by fixing the imaging element on the mounting plane of the package substrate such that the center of the imaging element is aligned with the center of a phantom line diagonally connecting the center of one of the positioning reference holes in one of the reference planes with the center of one of the reference holes in the other of the reference planes. A solid state imaging unit utilizing the imaging device includes a lens mirror cylinder unit having pin members engaging diagonally opposed ones of each of the at least one pair of positioning reference holes, a reference plane corresponding to the reference planes of the package substrate and an optical lens having an optical axis that passes through the center of a phantom line connecting the centers of the pin members and the center of the imaging element.