To enhance a pressure resistance and fatigue strength of a separator tube arranged in an outer circumferential zone of a cylinder, the separator tube having a branch tube integrally formed with the separator tube, thereby enabling weight reduction by thinning of the separator tube, in a cylindrical shock absorber.

A piston 5 coupled with a piston rod 6 is inserted in a cylinder 2 with oil liquid sealed therein, and a flow of the oil liquid caused by the movement of the piston 5 is controlled by a damping-force generation mechanism 25 to generate a damping force. A separator tube 20 is arranged in an outer circumferential zone of the cylinder 2, and the oil liquid is circulated to the damping-force generation mechanism 25 through a branch tube 45 integrally formed with a cylindrical sidewall of the separator tube 20. The branch tube 45 is formed by burring processing to the cylindrical sidewall of the separator tube 20. A recess obtained by recessing an inner circumference surface toward the outside in a radial direction of the separator tube is formed by pressing both sides of a base of the branch tube 45 in a circumference direction of the sidewall of the separator tube 20 from inside. Thereby, a residual stress of tension at the base of the branch pipe 45 is eliminated, and pressure resistance and fatigue strength are enhanced.