To make output control other than fixed temperature control possible and to widen the width of treatment contents.

A heating treatment device 1 comprises: coagulation/dissection forceps 2 for which a heating element 21 is provided in a treatment part 9; an applied current detection part 31 and an applied voltage detection part 32 for detecting a current value and a voltage value applied to the heating element 21; a control computation part 33 for computing one of a current, a voltage, power and a temperature in the heating element 21 by using the respective detected results of the applied current detection part 31 and the applied voltage detection part 32; an output setting part 35 for setting one of the current, the voltage, the power and the temperature in the heating element 21; an output control part 36 for controlling output to the heating element 21 on the basis of a computed result by the control computation part 33 and the setting of the output setting part 35; and a control selection switching part 39 for selecting one or more from constant current control, constant voltage control, constant power control and constant temperature control as the control contents of the output control part 36.