To suppress engine vibration, noises or the like in a wide vibration frequency area without increasing costs by a simple structure in a fluid mount device.

Main and sub fluid rooms 21 22 are provided in a housing 15, main and sub opening rooms 24 and 26 opened to the outer surface of the housing 15 and formed roughly in truncated chevron shapes are provided so as to be communicated with the main and sub fluid rooms 21 and 22, valve bodies for changing the opening amounts of the opening parts 24 and 26 are provided in the communications paths of the same so as to be freely moved, an ECU 33 moves the valve bodies by a driving motor 32 according to the rotational area of the engine, and thereby the length of the communication path and a sectional area are simultaneously changed.