A device (10) for the treatment of the skin, in particular for a non-invasive treatment of the skin tissue, the device comprising: - a laser source (40) for generating a laser beam (42) during a time of predetermined pulse, - a skin contact surface (14) with which the device (10), in use, is applied to the skin to be treated, and - an optical system (46, 48, 50) for focusing the laser beam (42) on a focal point (18), said optical system comprising a laser beam manipulator (46, 48) arranged to place the focal point (18) in a layer of skin dermis at a treatment depth between 0.2 and 2 millimeters below the skin contact surface (14), - in which a dimension of the focal point (18) and a power of the laser beam (42) generated are such that At the focal point, the laser beam has a power density that is above a characteristic threshold value for the tissue of l to skin in the dermis layer of the skin, value above which, for the predetermined pulse time, a phenomenon of laser-induced optical assignment occurs in the skin tissue (22, 24), - in which a level of energy available in the laser beam pulse is between 0.5 and 5 mJ measured on the skin contact surface (14), and in which the optical system has a numerical aperture of at least 0, 4, characterized in that the optical system comprises a control unit configured to control the laser beam manipulator based on position information of a locally depressed line of maximum skin depth, and because the laser beam manipulator is arranged to position the focal point with respect to said line.Un dispositivo (10) para el tratamiento de la piel, en concreto para un tratamiento no invasivo del tejido de la piel, comprendiendo el dispositivo: - una fuente de láser (40) para generar un haz de láser (42) durante un tiempo de pulso predeterminado, - una superficie de contacto con la piel (14) con la cual el dispositivo (10), en uso, se aplica a la piel que va a ser tratada, y - un sistema óptico (46, 48, 50) para enfocar el haz de láser (4
