Seat for military vehicle

The invention concerns a seat (1) for a military vehicle comprising on the one hand a backrest (3) and on the other hand a seat pan (4) for a passenger (2), the seat pan (4) being able to pivot around a pivot connection (6) to pass from a folded position where it is substantially parallel to the backrest (3) and an unfolded position where it is substantially perpendicular to the backrest (3), the freedom of pivoting of the pivot connection (6) being limited downward by at least one retaining means (7) able to release the lowering of the seat pan (4) beyond the unfolded position following an effort of a predetermined level resulting from a mine blast, seat (1) characterized in that the rear part of the seat pan (4) is integral with a lumbar support plate (9) substantially perpendicular to the seat pan (4) and able to pivot with the seat pan (4).