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 connected, at one end thereof, to the casing and connected, 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 comprises: a cylinder connected to one of the casing and the outer tub; and a piston connected to the other one of the casing and the outer tub, wherein the cylinder and the piston are configured to make relative movement with respect to each other according to movement of the outer tub, characterized by a slide member arranged to slide along the piston with a frictional contact with the piston; and a slide member guide interposed between the cylinder and the slide member and being rotatable between a first rotational position and a second rotational position with respect to the slide member, wherein the slide member guide is configured to move to the first rotational position when a level of vibration of the outer tub is equal to or higher than a certain level, and to the second rotational position when a level of vibration of the outer tub is lower than the certain level, wherein the slide member guide is configured to have a larger maximum allowable relative displacement with respect to the slide member at the second rotational position than at the first rotational position, and wherein friction between the slide member guide and the slide member is smaller than friction between the slide member and the piston. a casing; an outer tub supported in the casing; an inner tub rotatably provided in the outer tub; and a shock absorber connected, at one end thereof, to the casing and connected, 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 comprises: a cylinder connected to one of the casing and the outer tub; and a piston connected to the other one of the casing and the outer tub, wherein the cylinder and the piston are configured to make relative movement with respect to each other according to movement of the outer tub, characterized by a slide member arranged to slide along the piston with a frictional contact with the piston; and a slide member guide interposed between the cylinder and the slide member and being rotatable between a first rotational position and a second rotational position with respect to the slide member, wherein the slide member guide is configured to move to the first rotational position when a level of vibration of the outer tub is equal to or higher than a certain level, and to the second rotational position when a level of vibration of the outer tub is lower than the certain level, wherein the slide member guide is configured to have a larger maximum allowable relative displacement with respect to the slide member at the second rotational position than at the first rotational position, and wherein friction between the slide member guide and the slide member is smaller than friction between the slide member and the piston. a cylinder connected to one of the casing and the outer tub; and a piston connected to the other one of the casing and the outer tub, wherein the cylinder and the piston are configured to make relative movement with respect to each other according to movement of the outer tub, characterized by a slide member arranged to slide along the piston with a frictional contact with the piston; and a slide member guide interposed between the cylinder and the slide member and being rotatable between a first rotational position and a second rotational position with respect to the slide member, wherein the slide member guide is configured to move to the first rotational position when a level of vibration of the outer tub is equal to or higher than a certain level, and to the second rotational position when a level of vibration of the outer tub is lower than the certain level, wherein the slide member guide is configured to have a larger maximum allowable relative displacement with respect to the slide member at the second rotational position than at the first rotational position, and wherein friction between the slide member guide and the slide member is smaller than friction between the slide member and the piston.