A drilling mask for implanting a transpedicular screw on a spine section includes a guide body with a distal surface and a proximal surface, opposite to the distal surface and facing towards the spine section. The guide body includes a reference element obtained on the proximal surface and arranged to contact the spinous process, a guide channel that extends starting from the distal surface, which is arranged to work as drilling guide for drilling the pedicle and implanting the transpedicular screw, and a plurality of support elements made on the proximal surface, associated with the reference element, arranged to contact side parts of the spine section. The guide body also includes at least one reference portion.
