A control device (100) is a control device for an energy treatment tool including a first holding member (212) and a second holding member (214) which hold a biological tissue, and a heating element (224) configured to generate heat corresponding to supplied power, thereby heating the holding surface. The control device (100) includes a temperature acquiring section (140) that acquires a temperature of the heating element； and a surface temperature estimating section (150) that estimates, as a surface temperature, a temperature of at least a part of a surface of the first holding member which is different from a portion facing the second holding member, based on a change of the temperature of the heating element after supply of the power is stopped.
