A tool-holder head for machines using radiant energy beams, that is suitable in particular for plasma beam cutting machines, includes a vertical sliding saddle to which at least an energy beam source is constrained through an articulated support that secures the position of normal use of said source and allows the source to move according to the vertical axis or to translate according to said working position when transversal or axial forces are applied to said source's terminal part. The tool-holder bead is also equipped with sensing means of the above-said movings and translations so to be able to operate on the control of the machine with the more suitable proceedings according to the operating condition consequent to said senses.