A grasping treatment device includes a first sheath section, a second sheath section including a bending cylindrical section, and a rotating transmitting portion configured to rotate to allow a grasping section and the first sheath section to rotate in one of periaxial directions of a longitudinal axis with respect to the second sheath section. The grasping treatment device includes an opening/closing transmitting portion configured to move a movable portion of the first sheath section toward a proximal direction with respect to a probe fixed portion by being pulled toward the proximal direction, and an acting force transmitting portion configured to transmit an acting force from the probe fixed portion to the bending cylindrical section, the acting force being configured to act on the probe fixed portion from the movable portion toward the proximal direction.