A radiant heat sensor (101) includes a plate-shaped member (10), a plurality of first conductor patterns (41), and a plurality of second conductor patterns (42). The plate-shaped member (10) has a first surface (10a) and a second surface (10b), and includes a plurality of first thermoelectric members (31) and a plurality of second thermoelectric members (32) that are made of differing thermoelectric materials. The first thermoelectric members and the second thermoelectric members are alternately arrayed one by one in a direction along the first surface so as to be separated from each other, and each of the first thermoelectric members and second thermoelectric members configure a portion of the first surface. The plurality of first conductor patterns extend along the first surface, disposed on the first surface of the plate-shaped member so as to span a single first thermoelectric member and a single second thermoelectric member that are adjacent to each other, and configure hot contact portions between the first thermoelectric members and the second thermoelectric members. The plurality of second conductor patterns extend along the first surface, disposed on the first surface of the plate-shaped member so as to span a single first thermoelectric member and a single second thermoelectric member that are adjacent to each other, and configure cold contact portions between the first thermoelectric members and the second thermoelectric members.