To obtain a lens barrel whose productivity is excellent and which can be smoothly driven forward and backward as for the lens barrel having the forward and backward moving mechanism of a frame member.

In this lens barrel, a moving frame 5 is engaged in the inner circumferential part of a turnably supported rotary frame 2 and a cam frame M11 supporting a lens frame is supported in the inside of the frame 5 so that it can be turned and moved forward and backward. Besides, a straight advance groove 2a and a cam groove 5h whose width are enlarged and reduced in mutually opposite directions are formed in a radial direction at the frames 2 and 5 and tapered cam followers 17 and 18 engaged in the grooves are arranged. The shaft part of the follower 17 is press-fitted in the frame M11. Since the width of the grooves 2a and 2h are enlarged and reduced, thrust component force acting on the shaft part of the follower 17 is canceled.