An apparatus for the spraying of an area of interest (S) of a high-pressure working fluid (V) wherein the apparatus is susceptible to move relatively to the ground (S) along a direction of reciprocal advancement (d) and it comprises at least one tank (2) for the working fluid (V), at least one outlet nozzle (41) and a fluid connecting line (4) extending from the tank (2) towards the outlet nozzle (41). The apparatus further comprises supply means (5) of the working fluid (V) that include a high- pressure pump and at least one spraying device (10) placed along the fluid connecting line (4) the former (5) upstream with respect to the latter (10). Furthermore, the spraying device (10) comprises a support structure (11) that comprises a first plate (12), motor means (35) acting upon the first plate (12) to promote the eccentric rotation thereof around a first axis (Z) and at least one manifold (42) placed on the first plate (12) to move integrally therewith. In particular, the latter (42) comprises at least one outlet nozzle (41) oriented so as to spray a jet of working fluid (V) towards the ground (S). The first plate (12) is mounted movable with said support structure (11) so that upon the movement along the direction of reciprocal advancement (d) of the apparatus (1) and of the ground (S), the jet flowing from the outlet nozzle (41) hits the latter with helical path.