A ski boot includes a base shell; a sole; an upper shell that has at least a fastening clip and that is articulated to the base shell with pins provided in the region of the malleoli; an inner boot, wherein the base shell defines a slot having two strips coupled one to the other with a gaiter and is provided with at least one fastening device; a first tongue joined to the base shell in the proximity of a tip thereof, the first tong being manufactured from a material of differentiated rigidities, the portion of the first tongue in the area of the free end having a lower rigidity that the portion joined to the base shell; and a removable second tongue configured to cover the first tongue and having a greater rigidity than the first tongue.