An image sensor module includes an interposer substrate having a first surface and a second surface opposite to the first surface, the interposer substrate being light-transmissive and having a plurality of through-holes; an image sensor located to face the first surface of the interposer substrate, the image sensor having a light receiving surface on a side of the interposer substrate, a plurality of photoelectric conversion elements being located at the light receiving surface, the image sensor being connected with an external circuit via electrodes provided in the plurality of through-holes; and a lens unit located to face the second surface of the interposer substrate.