A medical treatment device includes: a pair of holding members configured to grasp a target part to be connected in a body tissue； an energy application portion provided on at least one holding member of the pair of holding members, the energy application portion being configured to contact the target part when the target part is grasped by the pair of holding members to apply energy to the target part； and a processor including hardware. The processor is configured to cause the energy application portion to: apply high-frequency energy to the target part for a first period； apply ultrasound energy to the target part for a second period subsequent to the first period； and apply heat energy to the target part for a third period subsequent to the second period.
