An optical sensor element is mounted in a package which includes a glass substrate having a cavity, and a glass lid substrate bonded to the other substrate to close the cavity. The glass substrate with the cavity has metalized wiring patterns on front and rear surfaces thereof, and a through hole filled with metal to form a through-electrode interconnecting the wiring patterns on the front and rear surfaces. A metalized wiring pattern on the rear surface of the glass lid substrate is electrically connected to the wiring pattern on the front surface of the other substrate with an adhesive containing conductive particles. The glass lid substrate is made either of glass having a filter function or glass having a light shielding property with an opening therethrough filled with glass having a filter function.