A child seat includes: a base member; a seat body switchable at least between a forward facing state and a sideways facing state in a bed shape on the base member; a prop or strut member attached to a front end of the base member and extending to a position where the prop member abuts on a floor of an automobile; and a rigid bar-shaped support member supported by the prop member so as to be displaceable between an upper position and a lower position. A side engagement portion is provided in a side surface of the seat body. The side engagement portion engages with the support member when the support member is brought to the upper position in the sideways facing state in the bed shape.