Conventionally, a device, which communicates a pressure by a fluid, such as oil, to communicate an operating amount at an action side from an operating side, has been used. In such a device, it is common to have a configuration, for example, such that oil in a cylinder is pushed out by pressing a piston on the operating side, and move the piston on the action side through an oil conducting tube, thereby the operating amount is communicated to a predetermined device. Such device is disclosed, for example, in Japanese Unexamined Patent Application No. H5-4570.
However, when the conventional operating device is applied to communicating an operating amount of fluid by using a foot brake operated by a foot, there has been an issue of difficulty in accurately communicating a subtle move of an operating side to an action side. Further, in a case when communicating an operating amount of fluid from the operating side to a plurality of pistons on the action side, the amount of movement for each piston on the action side may result in difference movements, thus there has been a problem of further difficulty in accurately communicating a subtle move to the action side.