A laundry processing machine comprising: a casing; an outer tub supported in the casing; an inner tub rotatably provided in the outer tub; and a shock absorber (200, 300, 400) coupled, at one end thereof, to the casing and coupled, at the other end thereof, to the outer tub to absorb vibration of the outer tub caused by rotation of the inner tub, wherein the shock absorber (200, 300, 400) comprises: a cylinder (230, 330) connected to one of the casing and the outer tub; a piston (220, 320, 420) connected to the other one of the casing and the outer tub, wherein the cylinder (230, 330) and the piston (220, 320, 420) make relative movement with respect to each other according to the movement of the outer tub; a friction member (241, 341, 441) provided to form friction with the piston (220, 320, 420); a friction member holder (242, 342, 442) to integrally move together with the friction member (241, 341, 441); and a holder operating member (252, 352, 452) to apply pressure to the friction member holder (242, 342, 442) to cause the friction member to contact the piston (220, 320, 420) when the holder operating member (252, 352, 452) is at a first operational position and to release the pressure applied to the friction member holder (242, 342, 442) to allow the friction member (241, 341, 441) to be separated from the piston (220, 320, 420) when the holder operating member (252, 352, 452) is at a second operational position, characterized in that the holder operating member comprises a cam forming portion protruding from an inner circumferential surface facing the friction member holder and extending along a circumferential direction, and the cam forming portion comprises: a pressing section to apply pressure to the friction member holder to allow the friction member to closely contact the piston, when the holder operating member is at the first operational position; and a spacing section to form a gap between the spacing section and the piston to allow the friction member holder separated from the piston to move, when the holder operating member is at the second operational position. a casing; an outer tub supported in the casing; an inner tub rotatably provided in the outer tub; and a shock absorber (200, 300, 400) coupled, at one end thereof, to the casing and coupled, at the other end thereof, to the outer tub to absorb vibration of the outer tub caused by rotation of the inner tub, wherein the shock absorber (200, 300, 400) comprises: a cylinder (230, 330) connected to one of the casing and the outer tub; a piston (220, 320, 420) connected to the other one of the casing and the outer tub, wherein the cylinder (230, 330) and the piston (220, 320, 420) make relative movement with respect to each other according to the movement of the outer tub; a friction member (241, 341, 441) provided to form friction with the piston (220, 320, 420); a friction member holder (242, 342, 442) to integrally move together with the friction member (241, 341, 441); and a holder operating member (252, 352, 452) to apply pressure to the friction member holder (242, 342, 442) to cause the friction member to contact the piston (220, 320, 420) when the holder operating member (252, 352, 452) is at a first operational position and to release the pressure applied to the friction member holder (242, 342, 442) to allow the friction member (241, 341, 441) to be separated from the piston (220, 320, 420) when the holder operating member (252, 352, 452) is at a second operational position, a cylinder (230, 330) connected to one of the casing and the outer tub; a piston (220, 320, 420) connected to the other one of the casing and the outer tub, wherein the cylinder (230, 330) and the piston (220, 320, 420) make relative movement with respect to each other according to the movement of the outer tub; a friction member (241, 341, 441) provided to form friction with the piston (220, 320, 420); a friction member holder (242, 342, 442) to integrally move together with the friction member (241, 341, 441); and a holder operating member (252, 352, 452) to apply pressure to the friction member holder (242, 342, 442) to cause the friction member to contact the piston (220, 320, 420) when the holder operating member (252, 352, 452) is at a first operational position and to release the pressure applied to the friction member holder (242, 342, 442) to allow the friction member (241, 341, 441) to be separated from the piston (220, 320, 420) when the holder operating member (252, 352, 452) is at a second operational position, characterized in that the holder operating member comprises a cam forming portion protruding from an inner circumferential surface facing the friction member holder and extending along a circumferential direction, and the cam forming portion comprises: a pressing section to apply pressure to the friction member holder to allow the friction member to closely contact the piston, when the holder operating member is at the first operational position; and a spacing section to form a gap between the spacing section and the piston to allow the friction member holder separated from the piston to move, when the holder operating member is at the second operational position. a pressing section to apply pressure to the friction member holder to allow the friction member to closely contact the piston, when the holder operating member is at the first operational position; and a spacing section to form a gap between the spacing section and the piston to allow the friction member holder separated from the piston to move, when the holder operating member is at the second operational position.