PURPOSE: To obtain the seat vibrating device by which a load and vibration to a vibration driving mechanism and the device base are small, and also, durability of the vibration driving mechanism is sufficient, and the manufacturing cost, the maintenance cost and a noise are small, and accordingly, whose profitability and environmental property are excellent.

CONSTITUTION: The device is provided with a seat 2 provided with a vibration generating machine 1, plural expandable/contractable type vertical elastic supporting bodies 4 for supporting a horizontal supporting plate for supporting the seat 2, on a rack base in at least three positions, respectively, a compressive fluid feed/discharge piping 6 connected to each vertical elastic supporting body, respectively from a compressive fluid generating device 7, and an automatic feed/discharge controller inserted into each compressive fluid feed/discharge piping 6, respectively.