Since a lower-surface side opening of an elevator housing slit is closed by a partition wall portion of a cap in normal operation, and a rotating shaft receiving portion of an elevator has a rotating shaft housing groove opened on the side opposite to the lower surface when the elevator is attached to a distal end portion body, the elevator is not removed structurally at an angle of the elevator when the treatment tool is operated to be stood, and a rotating shaft and the rotating shaft receiving portion do not have to be attached excessively tightly. Therefore, a work load in disassembling and assembling of a distal end portion can be set appropriately, and workability in disassembling and assembling is improved. Moreover, as a result, the distal end portion can be cleaned rapidly and easily.
