Low frequency vibration structure and low frequency vibration seat

The structure is formed by serially connecting a torsion bar and a coil spring via a arm and a supporting frame to thereby elastically support a flat-type supporting member, and by disposing a cushioning member for seat cushion provided with a spring characteristic closely analogous to a load-to-deflection characteristic (spring characteristic) of the muscle of a human body above the flat-type supporting member. Accordingly, it is possible to make a spring characteristic for working when supporting a load of a human different from a spring characteristic for working when removing vibration even with an extremely simple structure. In other words, the structure has an excellent function to make the spring constant at work when removing vibration, especially when removing a high frequency component.