To exercise a seal function and a release function of predetermined oil pressure at a check seal part without deteriorating ride comfort of a vehicle.

A rod guide 4 includes a sealing rib 11 of which upper end surface is formed in an annular shape and contacts a tip part 53a of a check seal part 53 over a whole circumference, and an inner circumference side rib 12 which is projectingly provided at a side near a rod body 3 than the sealing rib 11 and contacts a tip part 53a of the check seal part 53 at an upper end thereof to define an annular passage 21 together with the sealing rib 11. The inner circumference side rib 12 includes an oil pressure inducing means 12a allowing communication between an inner circumference side thereof and the annular passage 21.