A front fork comprises a telescopic tube (1, 32) in which a damper cylinder (3) generates a damping force. The damper cylinder (3) comprises a guide sleeve (4) and a free piston (6) having an inner circumference which slides on the outer circumference of the guide sleeve (4) and an outer circumference which slides on the inner circumference of the damper cylinder (3). A lateral through-hole (11) formed in the guide sleeve (4) connects an auxiliary reservoir (R3) formed outside the damper cylinder (3) and an oil reservoir (R2) via a flow path (12) formed in the guide sleeve (4) according to the displacement position of the free piston (6), thereby reducing the number of seal members required to be fitted on the outer circumference of the free piston (6) and enabling the free piston (6) to slide smoothly even when the telescopic tube (1, 32) suffers a bending force.