A seat in which a cushioning member has a high following ability to a human body motion and which can efficiently damp a vibration inputted from the outside is provided. The seat is constituted to use a torsion bar 112 and to support a cushioning member of a seat cushion section 150 by a parallel link mechanism having a first link plate 113 pivotally supported by the torsion bar 112, a second link plate 116 disposed in correspondence with the first link plate 113, and a connection link plate 117 connecting the first link plate 113 and the second link plate 116, and operational directions of the first link plate 113 and the second link plate 116 are set to almost coincide with a vertical direction along a surface of a seat back section. Thus, a rotational motion following a human body motion generated by an external vibration input is performed, so that a relative motion between a human body and the cushioning member is small and a resonance peak is lowered, whereby a vibration absorption characteristic can be improved.