The disclosure has a configuration including: a supporting substrate having a cavity; at least one bridge section extending directly above the cavity and having at least one end supported by the supporting substrate and an other end; and a thermopile wiring formed in the bridge section and including hot junctions in the bridge section and cold junctions directly above the supporting substrate, the hot junctions being connected to the cold junctions. The bridge section is provided with: at least one breakage detection wiring for detecting breakage of the bridge section; and at least one heater wiring. The breakage detection wiring is wired along the thermopile wiring. The heater wiring is wired such that part of the heater wiring is in an area between the other end of the bridge section and the hot junctions.