The treatment device (1) has a heat transfer member (122) which contacts the living tissue and transfers heat to the living tissue, and a heat generation member (128) which heats the heat transfer member. The treatment device (1) comprises a drive circuit (230) for supplying a constant voltage of a first voltage value and a second voltage value respectively to the heat generating member when it is on and off, and a length of an on period or an off period An offset value calculation section (212) for calculating an offset value according to the temperature difference between the heat transfer member and the heat generation member based on the length of the heat generation member, the offset value calculation section (212) An output setting section (213) for setting ON or OFF so as to maintain the ON / OFF state, and a drive control section (214) for controlling the operation of the drive circuit based on the set ON or OFF.処置装置(1)は、生体組織と接触し、生体組織に熱を伝える伝熱部材(122)と、伝熱部材を加熱する発熱部材(128)とを有する。処置装置(1)は、オン及びオフであるときに発熱部材に第1の電圧値及び第2の電圧値の定電圧をそれぞれ供給する駆動回路(230)と、オン期間の長さ又はオフ期間の長さに基づいて、伝熱部材と発熱部材との温度差に応じたオフセット値を算出するオフセット値算出部(212)と、目標温度にオフセット値を加えた修正目標温度に発熱部材の温度を維持するように、オン又はオフを設定する出力設定部(213)と、設定されたオン又はオフに基づいて、駆動回路の動作を制御する駆動制御部(214)とを備える。
