CYLINDER DEVICE

PROBLEM TO BE SOLVED: To improve practicality of a cylinder device which functions as a colloidal damper.SOLUTION: The cylinder device includes a sealing member 80 which has flexibility, has closely sealed spaces divided and formed in chambers 54 which are divided and formed by a housing 42 and a piston 44, seals a porous body 100 and a part 84 of operation fluid in the sealed spaces in a state that the porous body 100 and the part 84 of operation fluid are mixed and permits the change of the volume of the sealed spaces by elastic deformation of the sealing member itself, wherein, in accordance with the relative movement of two objects 26, 32, the amount of the operation fluid 84 flowing into fine pores of the porous body 100 is changed, thereby, the relative movement of the two objects 26, 32 is damped and, thereby, the cylinder device not only functions as the colloidal damper but also supports the object 32 located on the upper side of the two objects 26, 32 depending on both of a pressure in the sealed space and elastic reaction force of the sealing member 80 generated by such a state that the operation fluid 84 is caused to flow into the fine pores of the porous body 100.