PURPOSE: To obtain a barrel for an interchangeable lens where manual focusing or autofocusing is selected in a focusing means with one touch.

CONSTITUTION: When an operation ring 29 is pulled out from the state of an autofocusing function to the position of a manual focusing operation, a driven shaft 22 is moved to the left in figure (backward) in accordance with the movement of the operation ring 29, and meshing clutches 27 and 59 are disengaged, and a key 102 of the operation ring 29 is engaged with a key groove 103 of a rotary cylinder 4, thus making the manual focusing operation possible. The focusing driving force due to the manual operation of the operation ring 29 is transmitted to straightly feeding mechanisms 4, 5, 7, 8, and 9 directly. In the manual focusing operation, the rotation power of the manual focusing driving is not transmitted to the camera body, and a switch SW2 is opened.