PROBLEM TO BE SOLVED: To provide a temperature regulator for an agricultural cultivation facility which can temporarily store heat in a greenhouse warmed by sunlight in the ground and return the heat stored in the ground according to the state of the greenhouse, thereby efficiently utilizing thermal energy.SOLUTION: The temperature is regulated in the agricultural cultivation facility by using a hybrid heat source combining underground heat and a heat pump unit in which a second circulation path 8 for returning heat stored in a heat storage layer 4 to the inside of a greenhouse 2 which is separated from a first circulation path 6 for storing heat is provided, and an intermediate circuit 82 (heat pump unit) is provided between a heat source side circuit 81 and a utilization side circuit 84.SELECTED DRAWING: Figure 1【課題】日光により温められたハウス内の熱を地中内に一時的に蓄熱し、状況に応じて地中に蓄えた熱をハウス内に戻すことにより、効率的に熱エネルギーを利用することができる農業栽培施設の温度調節装置を提供する。【解決手段】蓄熱用の第１循環路６とは別に、蓄熱層４に蓄熱された熱をハウス２内に戻す第２循環路８を備え、熱源側回路８１と利用側回路８４との間に中間回路８２（ヒートポンプユニット）を設け、地中熱とヒートポンプユニットとを組み合わせたハイブリッド熱源を用いて農業栽培施設の温度調節する。【選択図】図１
