An operating head for a machine tool for machining flat and sheet-like pieces, such as panels or the like, said operating head comprising at least: - an electro spindle with a cylindrical head area provided with an attachment for the connection of a tool or of an auxiliary unit; and - a suction device of the cutting residues generated during machining; wherein said suction device comprises a hood which defines a main chamber which surrounds the head area of the electro spindle and which can be placed in fluid communication with suction means, wherein said hood is slidably mounted with respect to the axis of the electro spindle between a retracted position and an extended position, characterized in that said hood comprises a peripheral edge which defines a circular opening which, in the retracted position, is substantially aligned with the end of the head area of the electro spindle, said circular opening having a diameter greater than the diameter of the head area so that, in the retracted position of the hood, between said peripheral edge and said end of the head area there is an annular passage in communication with the main chamber, wherein the suction device further comprises a containment element applicable to at least one tool of an auxiliary unit, wherein said containment element comprises: - a flat annular element mounted substantially close to or aligned with the end of the head area of the electro spindle so as to obstruct the annular passage between it and the peripheral edge of the hood; and - at least one casing which surrounds at least in part said tool of the auxiliary unit forming at least one secondary chamber; wherein said secondary chamber communicates with an opening formed in the annular element which, in the aforementioned operating condition, flows into the main chamber so as to place said secondary chamber in communication with the suction means. - an electro spindle with a cylindrical head area provided with an attachment for the connection of a tool or of an auxiliary unit; and - a suction device of the cutting residues generated during machining; wherein said suction device comprises a hood which defines a main chamber which surrounds the head area of the electro spindle and which can be placed in fluid communication with suction means, wherein said hood is slidably mounted with respect to the axis of the electro spindle between a retracted position and an extended position, characterized in that said hood comprises a peripheral edge which defines a circular opening which, in the retracted position, is substantially aligned with the end of the head area of the electro spindle, said circular opening having a diameter greater than the diameter of the head area so that, in the retracted position of the hood, between said peripheral edge and said end of the head area there is an annular passage in communication with the main chamber, wherein the suction device further comprises a containment element applicable to at least one tool of an auxiliary unit, wherein said containment element comprises: - a flat annular element mounted substantially close to or aligned with the end of the head area of the electro spindle so as to obstruct the annular passage between it and the peripheral edge of the hood; and - at least one casing which surrounds at least in part said tool of the auxiliary unit forming at least one secondary chamber; wherein said secondary chamber communicates with an opening formed in the annular element which, in the aforementioned operating condition, flows into the main chamber so as to place said secondary chamber in communication with the suction means. wherein said suction device comprises a hood which defines a main chamber which surrounds the head area of the electro spindle and which can be placed in fluid communication with suction means, wherein said hood is slidably mounted with respect to the axis of the electro spindle between a retracted position and an extended position, characterized in that said hood comprises a peripheral edge which defines a circular opening which, in the retracted position, is substantially aligned with the end of the head area of the electro spindle, said circular opening having a diameter greater than the diameter of the head area so that, in the retracted position of the hood, between said peripheral edge and said end of the head area there is an annular passage in communication with the main chamber, wherein the suction device further comprises a containment element applicable to at least one tool of an auxiliary unit, wherein said containment element comprises: - a flat annular element mounted substantially close to or aligned with the end of the head area of the electro spindle so as to obstruct the annular passage between it and the peripheral edge of the hood; and - at least one casing which surrounds at least in part said tool of the auxiliary unit forming at least one secondary chamber; - a flat annular element mounted substantially close to or aligned with the end of the head area of the electro spindle so as to obstruct the annular passage between it and the peripheral edge of the hood; and - at least one casing which surrounds at least in part said tool of the auxiliary unit forming at least one secondary chamber; wherein said secondary chamber communicates with an opening formed in the annular element which, in the aforementioned operating condition, flows into the main chamber so as to place said secondary chamber in communication with the suction means.