To improve storing performance and carrying performance during non-use and diversify the usage in a child seat.

This child seat includes a seat part 1 and a backrest part 2 which are connected to vary the attitude, an attitude holding means 5 for holding the seat part 1 and the backrest part 2 in the using posture, and first side supports 3, 3 and second side supports 4, 4 provided to select between an erect attitude and a falling attitude on both side parts 1a, 1a, 2c, 2c in the cross direction of the seat part 1 and the backrest part 2. By this arrangement, the child seat can be functioned as the nature child seat, besides, it can be used as a bed for a child, and the storing performance and carrying performance of the child seat can be improved by storing the child seat in a compact manner.