A hydraulic shock absorber comprising: a cylinder; a first support member formed in one end portion of the cylinder; a cover member configured to close the other end portion of the cylinder; a main piston rod slidably extending through the first support member; a sub piston rod positioned on the same axis as that of the main piston rod, and connected to one end portion of the main piston rod which is positioned inside the cylinder; a pipe arranged in the cylinder in a state in which the pipe is positioned on the same axis as that of the main piston rod and the sub piston rod, and including one end portion fixed to the cover member and the other end portion into which a distal end portion of the sub piston rod is inserted; a second support member fixed to the other end portion of the pipe, and including an outer circumferential portion which has a diameter larger than that of the pipe and is fitted on an inner circumferential surface of the cylinder; a piston slidably fitted in the cylinder in a state in which the piston is fixed between the main piston rod and the sub piston rod, and configured to form a first oil chamber between the piston and the first support member and a second oil chamber between the piston and the second support member; a free piston slidably fitted between the pipe and the cylinder such that the pipe extends through the free piston, and configured to form a third oil chamber between the free piston and the second support member and a gas chamber between the free piston and the cover member; a first hydraulic oil passage (45,46,48,49) configured to make the first oil chamber and the second oil chamber communicate with each other; a valve (53,54) formed in the first hydraulic oil passage (45,46,48,49); and a second hydraulic oil passage formed in the second support member such that hydraulic oil can freely pass, and configured to make the second oil chamber and the third oil chamber communicate with each other, wherein the first oil chamber, the second oil chamber, and the third oil chamber are filled with the hydraulic oil, the gas chamber is filled with a gas having a pressure which pushes the free piston toward the second support member, a space in the pipe is a closed space, characterized in that the second support member including an inner circumferential portion which slidably supports the distal end portion of the sub piston rod; an outer diameter of a sliding portion of the main piston rod differs from that of a sliding portion of the sub piston rod, and a total sectional area of the second hydraulic oil passage is not less than a difference between a sectional area of the sliding portion of the main piston rod and that of the sliding portion of the sub piston rod. a cylinder; a first support member formed in one end portion of the cylinder; a cover member configured to close the other end portion of the cylinder; a main piston rod slidably extending through the first support member; a sub piston rod positioned on the same axis as that of the main piston rod, and connected to one end portion of the main piston rod which is positioned inside the cylinder; a pipe arranged in the cylinder in a state in which the pipe is positioned on the same axis as that of the main piston rod and the sub piston rod, and including one end portion fixed to the cover member and the other end portion into which a distal end portion of the sub piston rod is inserted; a second support member fixed to the other end portion of the pipe, and including an outer circumferential portion which has a diameter larger than that of the pipe and is fitted on an inner circumferential surface of the cylinder; a piston slidably fitted in the cylinder in a state in which the piston is fixed between the main piston rod and the sub piston rod, and configured to form a first oil chamber between the piston and the first support member and a second oil chamber between the piston and the second support member; a free piston slidably fitted between the pipe and the cylinder such that the pipe extends through the free piston, and configured to form a third oil chamber between the free piston and the second support member and a gas chamber between the free piston and the cover member; a first hydraulic oil passage (45,46,48,49) configured to make the first oil chamber and the second oil chamber communicate with each other; a valve (53,54) formed in the first hydraulic oil passage (45,46,48,49); and a second hydraulic oil passage formed in the second support member such that hydraulic oil can freely pass, and configured to make the second oil chamber and the third oil chamber communicate with each other, wherein the first oil chamber, the second oil chamber, and the third oil chamber are filled with the hydraulic oil, the gas chamber is filled with a gas having a pressure which pushes the free piston toward the second support member, a space in the pipe is a closed space, characterized in that the second support member including an inner circumferential portion which slidably supports the distal end portion of the sub piston rod; an outer diameter of a sliding portion of the main piston rod differs from that of a sliding portion of the sub piston rod, and a total sectional area of the second hydraulic oil passage is not less than a difference between a sectional area of the sliding portion of the main piston rod and that of the sliding portion of the sub piston rod.