Child seat

In a child seat (1) comprising a base unit (2) placed on a seat (100) of a vehicle and a seat unit (3) placed on the base unit in a forward attitude with respect to the seat of the vehicle, the base unit is provided with a base body (2a) to be fixed to the seat, a slider (5) connected to the base body in a positionally adjustable manner in a longitudinal direction of the seat of the vehicle, and a restraining belt device (4) for restraining a child sitting on the seat unit, and the seat unit is provided with a seat cushion portion (6) integrally connected to the slider in a positionally adjustable and detachable manner, and a seat back portion (8) connected to the rear end of the seat cushion in a manner turnable about an axis extending in a lateral direction of the seat and connected at the back side thereof to the base unit in a detachable manner.