Provided is a damping device including a cylindrical body sealed with an inner cover and an outer cover at both ends, a support rod coupled to one end of the cylindrical body to perform an axial motion, the support rod including a moving plate having a damping orifice in the cylindrical body, the support rod including a nut configured to adjust a length of the support rod at an inner side end received in the cylindrical body, and a buffering device configured to store elastic energy in one of a first spring and a second spring based on a moving direction of the moving plate, the buffering device including the first spring inserted in the inner cover, the second spring inserted in the outer cover, and a lubricant in the cylindrical body.