SHOCK ABSORBER

A shock absorber includes ; a free piston (9) that partitions the compression chamber (R3) into an expansion-side compression chamber (7) and a contraction-side compression chamber (8); a spring member (10) configured to generate a biasing force for the free piston (9); an expansion-side flow passage (5) that connects the expansion-side chamber (R1) with the expansion-side compression chamber (7); a contraction-side flow passage (6) that connects the contraction-side chamber (R2) with the contraction-side compression chamber (8); an expansion-side bypass valve (15) arranged closer to the expansion-side chamber (R1) side relatively to the piston (2) and provided in the expansion-side flow passage (5), the expansion-side bypass valve (15) being configured to admit only a flow directed from the expansion-side chamber (R1) to the expansion-side compression chamber (7) and generate resistance; a contraction-side bypass valve (16) provided in parallel with the expansion-side bypass valve (15) to admit only a flow directed from the expansion-side compression chamber (7) to the expansion-side chamber (R1) and generate resistance; an expansion-side elastic stopper (17) configured to stop the free piston (9) at an expansion-side stroke end; and a contraction-side elastic stopper (18) configured to stop the free piston (9) at a contraction-side stroke end.