To provide an operating device and a suspension specifying the separation limit of two members that approach and separate from each other and shutting off an approaching/separating part from the outside with simple and compact constitution.

A boot 24 of hollow cylinder shape is disposed between a housing 40 of an approaching/separating direction force generating device and a housing 106 of a passive expansion device. The boot 24 comprises a bellows part 156 formed by arranging large diameter parts 152 and small diameter parts 154 alternately in an axial direction, wherein a plurality of wires 158 are embedded in a peripheral wall 150 along each plane including the axis of the boot 24 and along the curve of the bellows part 156. In the boot 24, the large diameter parts 152 and small diameter parts 154 are compressed to allow the approach of the housings 40, 106 when a vehicle bounds, and extended to allow the separation of the housings 40, 106 when rebounding. The wires 158 are also extended and compressed but apply tension to the housing 40, 106 at the extension limit to specify the separation limit.