An infrared sensor chip (3; 31), comprising: 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 at least one bridge section , the thermopile wiring including hot junctions and cold junctions , the hot junctions being connected to the cold junctions , the hot junctions being provided in the at least one bridge section , the cold junctions being provided directly above the supporting substrate , the at least one bridge section being provided with: at least one breakage detection wiring for detecting breakage of the at least one bridge section ; and at least one heater wiring (22; 32), the at least one breakage detection wiring being wired along the thermopile wiring , the at least one heater wiring (22; 32) being wired such that part of the at least one heater wiring (22; 32) is in an area between the other end of the at least one bridge section and the hot junctions , wherein the at least one breakage detection wiring includes two first wiring sections extending in a first direction in which the at least one end and the other end are aligned and a second wiring section having both ends connected to ends of the two first wiring sections at the other end , the at least one heater wiring (22; 32) includes a lead line section wired outside the area and having an end in the area and a heater section connected to an end of the lead line section and wired in the area , wherein the heater section is made of polysilicon, characterized in that the lead line section is made of metal. 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 at least one bridge section , the thermopile wiring including hot junctions and cold junctions , the hot junctions being connected to the cold junctions , the hot junctions being provided in the at least one bridge section , the cold junctions being provided directly above the supporting substrate , the at least one bridge section being provided with: at least one breakage detection wiring for detecting breakage of the at least one bridge section ; and at least one heater wiring (22; 32), the at least one breakage detection wiring being wired along the thermopile wiring , the at least one heater wiring (22; 32) being wired such that part of the at least one heater wiring (22; 32) is in an area between the other end of the at least one bridge section and the hot junctions , wherein the at least one breakage detection wiring includes two first wiring sections extending in a first direction in which the at least one end and the other end are aligned and a second wiring section having both ends connected to ends of the two first wiring sections at the other end , two first wiring sections extending in a first direction in which the at least one end and the other end are aligned and a second wiring section having both ends connected to ends of the two first wiring sections at the other end , the at least one heater wiring (22; 32) includes a lead line section wired outside the area and having an end in the area and a heater section connected to an end of the lead line section and wired in the area , wherein a lead line section wired outside the area and having an end in the area and a heater section connected to an end of the lead line section and wired in the area , wherein the heater section is made of polysilicon, <EOS>