The present invention provides a temperature control unit capable of efficiently controlling a temperature of a specific object with reduced risk of failure of electronic components due to leakage of a temperature control medium. The temperature control unit (1), which controls a temperature of a specific object, contains a temperature control medium, and a metal fiber sheet (50) that is formed with a space serving as a channel of the temperature control medium. The latent heat of evaporation of the temperature control medium is within the range of from 70 to 200 kJ/kg when the temperature control medium changes the state from a liquid state to a gaseous state. The volume expansion rate of the temperature control medium is at most 250 times when the temperature control medium changes the state from a liquid state to a gaseous state under atmospheric pressure.