Deep body thermometer

A deep body thermometer includes a thermal resistor having a predetermined thermal resistance value, first and second temperature sensors that sandwich the thermal resistor in a thickness direction of the thermal resistor, and a temperature information processing unit to acquire a deep body temperature based on the thermal resistance value of the thermal resistor, a temperature detected by the first temperature sensor, and a temperature detected by the second temperature sensor. The first and second temperature sensors are disposed such that the first and second temperature sensors do not overlap each other as viewed from the thickness direction of the thermal resistor and a distance between the first temperature sensor and the second temperature sensor is greater than a thickness of the thermal resistor.