Patent ID: 8519336

Claim:
An infrared sensor comprising: a first substrate transmitting infrared light and comprising at least one reduced-pressure and sealed cavity; at least one infrared sensing unit provided on a side of the first substrate opposite to a side intended to receive infrared light from the outside, the at least one infrared sensing unit generating an output change upon receipt of the infrared light passed through the at least one reduced-pressure and sealed cavity, the at least one reduced-pressure and sealed cavity being formed inside the first substrate at a position where the infrared sensing unit is arranged; a second substrate stacked on the first substrate and comprising: at least one recess forming a reduced-pressure space surrounding the at least one infrared sensing unit in cooperation with the first substrate, and a reflection face capable of reflecting the infrared light passed through the first substrate and not intercepted by the at least one infrared sensing unit toward the at least one infrared sensing unit; and at least one arithmetic circuit amplifying or integrating an output of the at least one infrared sensing unit, the at least one arithmetic circuit being integrated with the at least one infrared sensing unit and arranged in such a manner that the reflection face is sandwiched between the at least one infrared sensing unit and the at least one arithmetic circuit.