An endoscopic treatment tool includes a sheath, a support portion which is attached to a distal end side of the sheath, a pair of forceps members which are supported to be rotatable around a rotation axis provided on the support portion, a linear portion which is inserted through the sheath, the linear portion causing facing surfaces each provided on the forceps members to approach each other, as the distal end portion of the linear portion is separated from the rotation axis, and the linear portion separating the pair of facing surfaces from each other, as the distal end portion of the linear portion approaches to the rotation axis, an engaging portion which is provided in the support portion, an engaged portion which is provided in the linear portion, and a moving mechanism that moves the position of the distal end portion of the linear portion from a reference position to a distal end position closer to the distal end side than the reference position in a longitudinal direction of the sheath.
