A buffer includes a first seal portion, a second seal portion, a washer, and a bent portion. An annular body is provided between the washer and a rod guide, the first seal portion is provided on the inner peripheral side of the washer, or the inner peripheral side of the annular body, and the rod guide and an outer cylinder are radially spaced apart from each other at least on one end side of the outer cylinder. The outer peripheral side of the annular body has a bent portion bent and extending to the portion where the rod guide and the outer cylinder are radially spaced apart from each other, and the second seal portion is provided on the outer peripheral side of the bent portion.