Abstract: Ski boot made of plastic material consisting of:a deformable shell having two tongues which overlap to form flaps over the top of the foot;a cuff with a hinge on the shell shaped to form, at the front, two straps forming flaps over the front of the lower part of the leg;closing devices intended to slide the flaps over each other and thereby secure the foot in the shell and the lower part of the leg in the cuff;wherein the flap of the shell which corresponds to the outside edges of the foot covers the flap of the inside edge of the foot, whereas the flap which corresponds to the inside edge of the cuff covers the flap of the outside edge of the cuff.