A treatment tool (37, 37A, 37B) for an endoscope comprising: a distal end member that is adapted to be attached to a distal end of an endoscope and has a cylindrical shape; a treatment part configured to perform treatment on biological tissues; a tube that is arranged substantially parallel to an axis of the distal end member, arranged at a side surface of the distal end member, and arranged to be capable of advancing and retracting in an axis direction of the endoscope, the tube having a lumen formed therein; an insertion part that is inserted into the lumen, and arranged to be capable of advancing and retracting along the lumen, the insertion part having a distal end to which the treatment part is fixed; a moving member in which the tube is fixed; and a connecting member (38, 38A) that includes a first pivot (39, 39A) which has a first central axis extending in a direction perpendicular to an axis of the moving member and which is coupled with the moving member such that the first pivot (39, 39A) is capable of rotating about the first central axis relative to the moving member, and a second pivot which has a second central axis substantially parallel to the first central axis of the first pivot (39, 39A) and which is coupled with the distal end member such that the second pivot is capable of rotating about the second central axis relative to the distal end member, the connecting member (38, 38A) being configured to connect the first pivot (39, 39A) and the second pivot, wherein: the tube is configured to hold the insertion part; the second pivot is coupled with the distal end member such that the first pivot (39, 39A) is capable of rotating about the second central axis of the second pivot, the first pivot (39, 39A) is longer than a width of the moving member; and the tube is coupled with the first pivot (39, 39A) such that the tube is capable of moving relative to the first pivot (39, 39A) in a direction in which the first central axis of the first pivot (39, 39A) extends. a distal end member that is adapted to be attached to a distal end of an endoscope and has a cylindrical shape; a treatment part configured to perform treatment on biological tissues; a tube that is arranged substantially parallel to an axis of the distal end member, arranged at a side surface of the distal end member, and arranged to be capable of advancing and retracting in an axis direction of the endoscope, the tube having a lumen formed therein; an insertion part that is inserted into the lumen, and arranged to be capable of advancing and retracting along the lumen, the insertion part having a distal end to which the treatment part is fixed; a moving member in which the tube is fixed; and a connecting member (38, 38A) that includes a first pivot (39, 39A) which has a first central axis extending in a direction perpendicular to an axis of the moving member and which is coupled with the moving member such that the first pivot (39, 39A) is capable of rotating about the first central axis relative to the moving member, and a second pivot which has a second central axis substantially parallel to the first central axis of the first pivot (39, 39A) and which is coupled with the distal end member such that the second pivot is capable of rotating about the second central axis relative to the distal end member, the connecting member (38, 38A) being configured to connect the first pivot (39, 39A) and the second pivot, wherein: the tube is configured to hold the insertion part; the second pivot is coupled with the distal end member such that the first pivot (39, 39A) is capable of rotating about the second central axis of the second pivot, the first pivot (39, 39A) is longer than a width of the moving member; and the tube is coupled with the first pivot (39, 39A) such that the tube is capable of moving relative to the first pivot (39, 39A) in a direction in which the first central axis of the first pivot (39, 39A) extends. the tube is configured to hold the insertion part; the second pivot is coupled with the distal end member such that the first pivot (39, 39A) is capable of rotating about the second central axis of the second pivot, the first pivot (39, 39A) is longer than a width of the moving member; and the tube is coupled with the first pivot (39, 39A) such that the tube is capable of moving relative to the first pivot (39, 39A) in a direction in which the first central axis of the first pivot (39, 39A) extends.