Abstract: The safety seat comprises two parts and side walls. One seat part defines a seating, at least a rear part of the side walls and an arrangement for fixing the safety seat to a vehicle seat. The other seat part comprises a band and at least a front part of the side walls. A joint line of separation between the two seat parts has the shape of an L in the substantially vertical branch of which the energy absorbing and locking devices are located on each side of the safety seat whereas the substantially horizontal branch of the L constitutes an arrangement for guiding the two seat parts relative to each other.