an object is to prevent a reduction of definition caused when reflected light enters a photoelectric conversion element arranged at a periphery of a photoelectric conversion element arranged at a predetermined address . a semiconductor device is manufactured through the steps of : forming a structure having a first light - transmitting substrate , a plurality of photoelectric conversion elements over the first light - transmitting substrate , a second light - transmitting substrate provided so as to face the plurality of photoelectric conversion elements , a sealant arranged so as to bond the first light - transmitting substrate and the second light - transmitting substrate and surround the plurality of photoelectric conversion elements ; and thinning the first light - transmitting substrate by wet etching .