To safely deal with the vertical movement and the horizontal movement of a floating pier by fitting a cushioning body to the side of a floating pier, and slidably face-contacting a plate-like slide member fixed on the front face of the cushioning body with the side of a mooring pile.

A cushioning body 1 having fixed thickness is fitted to the side B1 of a floating pier B, and a plate-like slide member 3 is fixed on the front face of the body 1 through a connecting plate 2 made of metal such as steel plate. The slide member 3 is face-contacted with the side of a mooring pile P in the fixed state. In this case, the coefficient μ of statical friction of the surface of the slide member 3 against material constituting the objective face of the face contact is set to be under 0.4. Hereby, by a simple construction, this device can sufficiently deal with not only the vertical movement of the floating pier B but the horizontal movement, and it can be prevented from easily breaking down.