A medical treatment endoscope (300, 320) comprising: a first sheath having pivotal joint rings (305, 307) attached thereto and openings at the tip thereof; a second sheath disposed protruding from the first sheath, the second sheath having a first arm member, the first arm member having a first bending part and a second bending part, the first bending part having pivotal first joint rings attached thereto, the second bending part having a tip and a base end so that the tip end is connected to a base end of the first bending part and the base end is connected to the tip of the first sheath; a third sheath having a second arm member having the first bending part and the second bending part, the third sheath being disposed to protrude from the first sheath; a first operating member inserted through the first bending part and the second bending part and configured to bend the first bending part; a second operating member inserted through the second bending part and configured to bend the second bending part; a viewing device disposed at the tip of the first sheath independently from the second sheath and the third sheath and configured to observe an object; an illuminating member, configured to illuminate light to the object, disposed at the tip of the first sheath independently from the viewing device, the second sheath, and the third sheath; and a storage sheath including a first arm member lumen configured to allow the first arm member to be inserted therethrough, a second arm member lumen configured to allow the second arm member to be inserted therethrough, and a plurality of extension/retraction operating members, wherein a first one of the plurality of extension/retraction operating members connects the second bending part of the first arm member with the storage sheath, and a second one of the plurality of extension/retraction operating members connects the second bending part of the second arm member with the storage sheath, and tensile force is applied to the plurality of extension/retraction operating members by moving the storage sheath relative to the first arm member and the second arm member such that the first arm member and the second arm member protrude from a tip end of the storage sheath, and the tensile force causes the second bending part of the first arm member and the second bending part of the second arm member to bend. a first sheath having pivotal joint rings (305, 307) attached thereto and openings at the tip thereof; a second sheath disposed protruding from the first sheath, the second sheath having a first arm member, the first arm member having a first bending part and a second bending part, the first bending part having pivotal first joint rings attached thereto, the second bending part having a tip and a base end so that the tip end is connected to a base end of the first bending part and the base end is connected to the tip of the first sheath; a third sheath having a second arm member having the first bending part and the second bending part, the third sheath being disposed to protrude from the first sheath; a first operating member inserted through the first bending part and the second bending part and configured to bend the first bending part; a second operating member inserted through the second bending part and configured to bend the second bending part; a viewing device disposed at the tip of the first sheath independently from the second sheath and the third sheath and configured to observe an object; an illuminating member, configured to illuminate light to the object, disposed at the tip of the first sheath independently from the viewing device, the second sheath, and the third sheath; and a storage sheath including a first arm member lumen configured to allow the first arm member to be inserted therethrough, a second arm member lumen configured to allow the second arm member to be inserted therethrough, and a plurality of extension/retraction operating members, wherein a first one of the plurality of extension/retraction operating members connects the second bending part of the first arm member with the storage sheath, and a second one of the plurality of extension/retraction operating members connects the second bending part of the second arm member with the storage sheath, and tensile force is applied to the plurality of extension/retraction operating members by moving the storage sheath relative to the first arm member and the second arm member such that the first arm member and the second arm member protrude from a tip end of the storage sheath, and the tensile force causes the second bending part of the first arm member and the second bending part of the second arm member to bend.