Abstract: The present invention relates to a continuous filtration device in a liquid path, characterized in that it comprises, in combination: a modular ultrasonic treatment unit (12) which is in the form of a tubular metal body (11) with a cylindrical internal surface (13) and of circular cross section, open at both its feed end (10) and its discharge end (15), the external surface of the said tubular metal body having, in the vicinity of the nodal zone, a collar (17) which is coaxial with the said tube and which projects radially, this collar being equipped at its periphery with an ultrasonic converter (19) which projects radially and whose frequency is equal to the vibration frequency of the said collar (17) and to the longitudinal vibration frequency of the said tubular metal body (11), and a filtering cylindrical element (14) having a minimum filtration area of about 50 cm2 and preferably about 80 cm2 with a mesh opening less than about 20 ?m, which is arranged inside the tubular metal body (11) and coaxially

Abstract: The invention concerns a method for the treatment, in particular cosmetic, of an area of the skin of a human subject transepidermally, comprising the step consisting of spraying a pressurised liquid onto the area to be treated, by means of a spray nozzle (25). The invention also concerns a device for implementing such a method, as well as a hand piece for such a device.