A solid-state imaging device, comprises: a semiconductor substrate having a first surface; a solid-state imaging element in the first surface of semiconductor substrate, the solid-state imaging element comprising a light-receiving region; a light-transmission member having a second surface and a third surface, the second surface being opposite to the third surface, wherein the light-transmission member and the first surface of the semiconductor substrate define a gap between the second surface of the light-transmission member and an outer surface of the light-receiving region; and an external connection terminal connected to the solid-state imaging element, wherein the light-transmission member comprises low .alpha.-ray glass.