An automatic applicator of injection is described, which is equipped with a programmable electronic module that activates a first linear motor (ML1) which axially displaces an arm (13) of the proximal end (11) to the fixed head (20) placed at the distal end of the housing (10), said arm (13) which compresses a cartridge (15) fitted in the chamber (12) formed between the head (20) and the free end of the arm (13) so as to gradually expel the fluid stored in the cartridge； and a second linear motor (ML2) actuated concurrent with the first linear motor (ML1), said second linear motor (ML2) retreating an arm (60) with a dragger (61) which slides axially a suction chamber (30) toward the intermediate portion of the housing (10) and contiguous to the outer surface of the inner chamber (12), gradually exposing the needle tip (50) for application of the injection. The equipment is also equipped with a motor (63) which vibrates the suction chamber (30), tightly sealed, inside which air is removed by a suction pump creating a vacuum for the suction of the mucous against the needle.
