An infrared sensor including a substrate, a plurality of infrared detection pixels arrayed on a substrate with each of the infrared detection pixels including an infrared absorption portion formed over the substrate and configured to absorb infrared radiation, a thermoelectric converter portion formed over the substrate and configured to convert a temperature change in the infrared absorption portion into an electrical signal, and support structures configured to support the thermoelectric converter portion and the infrared absorption portion over the substrate via a separation space, the support structures having conductive interconnect layers configured to deliver the electrical signal from the thermoelectric converter portion to the substrate. The infrared sensor further includes a pixel selection circuit configured to select at least one of the infrared detection pixels which delivers the electrical signal and an output circuit configured to output the electrical signal delivered from selected infrared detection pixels via the conductive interconnect layers. The conductive interconnect layers include a material the same as a material of gate layers of the MOS transistors, and have a thickness similar to the gate layers.