A lens barrel includes a first lens holding member holding a first lens group, a second lens holding member holding a second lens group and an adjustment mechanism capable of adjusting the position of the first lens holding member relative to the second lens holding member. On a first plane of the second lens holding member, provided are at least three positioning parts abutting on the first lens holding member at positions surrounding the second lens group, and a sheet member attached to the first plane at a position surrounding the three positioning parts. The sheet member is pressed against the first lens holding member in the photographing optical axis direction while surrounding the first lens group throughout, between the adjustment mechanism and the first plane when viewed in the photographing optical axis direction.