A temperature measurement device includes a temperature measurement part, a calculation part, and a control part for controlling the operation of the temperature measurement part and the calculation part; wherein the temperature measurement part has a substrate having a first surface as a contact surface with a measured body, and a second surface as an environment-side surface which is opposite the first surface; a first temperature sensor; a second temperature sensor; and an environment temperature acquiring part; and the first temperature sensor and the second temperature sensor measure a first temperature and a second temperature a plurality of times under conditions in which a third temperature varies; and the calculation part calculates a deep temperature in a deep part of the measured body, on the basis of a deep temperature calculation equation, by using the measured temperatures.