Vertically movable seat structure

The invention consists of a vertically mobile seat structure (1) for a military vehicle comprising a vertical guidance means (6) of the movement of the seat (3) relative to a body (2) of the vehicle, guidance means (6) incorporating a release means (12) capable of releasing the vertical movement of the seat (3) following a vertical impact of a certain level, seat structure (1) characterized in that it comprises a retention means (13) of the seat (3) capable of preventing sudden upward movements thereof.