To prevent a folded-up seat from easily falling and turning by its dead weight while preventing easy assembling of a chair in the folding chair capable of folding up and turning the seat.

Left/right legs are integrally connected by a lateral member and a screw cylindrical bearing 11 is concentrically projected to the inside surfaces of the left/right legs. A support frame 9 comprising the seat is penetrated by a bolt 12 and rotationally supported by screwing the bolt 12 into the bearing 11. A cylindrical synthetic resin braking member 28 is fitted in the bearing 11 and the braking member 28 is formed with a pushing pressure part 28a abutting on the support frame 9 in its deflection deformed state.