Abstract: The invention is a device for removably blocking a central-front part of a ski boot to a ski platform for actuating a Telemark technique. The boot sole (51) forms, at a bottom thereof, two lateral edges, internal and external (52A, 52B). A plate (1) is blockable to the ski platform, a blocking device (17, 18) constrained to the plate, which bear at least two ratchets. The ratchets are associated with the bottom of the boot supported by the plate, to corresponding edges of the internal edge (52A) and external edge (52B). An activator (16, 24) for the blocking device is supported by the plate, defining two configurations of the blocking device, respectively inoperative (11), with a disengagement of the ratchets from the corresponding edges (52A, 52B) and operative (12), with a blocking of the two edges against the plate (1).