A thermal request mediating device that is mounted in a vehicle including a first thermal circuit (HT) configured to circulate a high-temperature coolant, a second thermal circuit (LT) configured to circulate a low-temperature coolant, a third thermal circuit (RE) configured to circulate a refrigerant while changing a state of the refrigerant and to exchange heat with the first thermal circuit and the second thermal circuit, and a plurality of units configured to perform absorption or discharge of heat via any one of heat mediums which circulate in the first thermal circuit, the second thermal circuit, and the third thermal circuit, the thermal request mediating device comprising: an acquisition unit configured to acquire amounts of heat which are requested by the plurality of units, the amounts of heat being amounts of absorbed heat or amounts of discharged heat; a calculation unit configured to calculate amounts of heat which are requested by the first thermal circuit, the second thermal circuit, and the third thermal circuit based on the amounts of heat which are requested by the plurality of units and which are acquired by the acquisition unit; characterized in that said thermal request mediating device further comprises a mediation unit configured to determine amounts of heat which are allocated to the first thermal circuit, the second thermal circuit, and the third thermal circuit based on the amounts of heat which are requested by the first thermal circuit, the second thermal circuit, and the third thermal circuit, an amount of heat transferable from the second thermal circuit to the third thermal circuit, and an amount of heat transferable from the third thermal circuit to the first thermal circuit; and a distribution unit configured to distribute amounts of heat to the units which are included in the first thermal circuit, the second thermal circuit, and the third thermal circuit based on the amounts of heat determined by the mediation unit. an acquisition unit configured to acquire amounts of heat which are requested by the plurality of units, the amounts of heat being amounts of absorbed heat or amounts of discharged heat; a calculation unit configured to calculate amounts of heat which are requested by the first thermal circuit, the second thermal circuit, and the third thermal circuit based on the amounts of heat which are requested by the plurality of units and which are acquired by the acquisition unit; characterized in that said thermal request mediating device further comprises a mediation unit configured to determine amounts of heat which are allocated to the first thermal circuit, the second thermal circuit, and the third thermal circuit based on the amounts of heat which are requested by the first thermal circuit, the second thermal circuit, and the third thermal circuit, an amount of heat transferable from the second thermal circuit to the third thermal circuit, and an amount of heat transferable from the third thermal circuit to the first thermal circuit; and a distribution unit configured to distribute amounts of heat to the units which are included in the first thermal circuit, the second thermal circuit, and the third thermal circuit based on the amounts of heat determined by the mediation unit. <EOS>