A grasping treatment device includes a probe including, in its distal portion, a first electrode portion, and a jaw grasping a grasping target between the first electrode portion and thereof and including a second electrode portion. The grasping treatment device includes a grasping force converting unit converting a grasping force so that a second grasping force between the first electrode portion and the jaw in a second treatment mode in which a high-frequency current alone is transmitted to the first electrode portion and the second electrode portion is greater than a first grasping force between the first electrode portion and the jaw in a first treatment mode in which at least the ultrasonic vibration is transmitted to the first electrode portion of the probe.