Abstract: The tool holder device for broaching and slotting, comprising: one main frame associated with one machine adapted to machine one workpiece; one working assembly associated with the main frame and comprising one supporting bar movable longitudinally along a first axis and a guiding mechanism for the supporting bar movable longitudinally along the first axis; one tool associated with the supporting bar and adapted to machine the workpiece; angular adjustment mechanism for adjusting the supporting bar, interposed between the main frame and the guiding mechanism and adapted to rotate the supporting bar around a second axis substantially orthogonal with respect to the first axis; and straight adjustment mechanism for adjusting the tool with respect to the supporting bar, interposed between the tool and the supporting bar, the straight adjustment mechanism being adapted to adjust the position of the tool along the second axis.