Abstract: Provided are an isolating device, a method of replacing an isolating structure part, and a method of controlling a load of the isolating structure part. The isolating device disposed between an upper structure and a lower structure includes an isolating structure part for performing an isolating function, and a height-adjustable part disposed on at least one of positions between the isolating structure part and the upper structure and between the isolating structure part and the lower structure, the height-adjustable part being adjusted in height by supplying or discharging fluid therein or therefrom.