Device for forming a hole through a glass plate, comprising a drilling tool having an axis, and a control device (105, 106, 107, 109, E) for controlling a rotation of the drilling tool around its axis and for simultaneously moving said drilling tool in the direction of said axis against and through said glass plate, so as to form a hole through the glass plate, said control device (105, 106, 107, 109, E) being configured for imparting said drilling tool also with a planetary movement around a main axis parallel and spaced apart from the axis of the drilling tool, so that said drilling tool is able to advance progressively through the glass plate during drilling of the hole by rotating around its axis and at the same time performing a helical movement resulting from the sum of said axial movement and said planetary movement around said main axis, wherein: - said drilling tool has an axial stem and an abrasive front surface, - said axial stem also has an abrasive surface, having however a grain size smaller than that of the front surface of the drilling tool, said axial stem being adapted to be engaged against the surface of the hole in the glass plate after that the hole has been obtained, in order to enlarge the diameter of the hole, said device being characterized in that: - said abrasive front surface has a substantially spherical shape, - said control device (105, 106, 107, 109, E) includes an electronic control unit programmed for imparting the drilling tool with a pulsed axial movement through the glass plate, comprising a succession of forward movements alternated with stops and/or rearward movements, and in that said device is an electronically controlled machining center comprising: - a work surface, - a working head movable along three mutually orthogonal directions (X, Y, Z) above the work surface, - a motorized spindle provided on the work head and carrying said drilling tool, for rotating the drilling tool around its axis, and - an electronic control unit which can be programmed for controlling the movements of the working head along said three orthogonal axes (X, Y, Z), - said device being further characterized in that said axial movement of the drilling tool is obtained by movement of said working head along one of said three orthogonal axes (X, Y, Z,) and the planetary movement of the drilling tool is obtained by coordinated movements of the working head along the remaining two axes (X, Y) of said three orthogonal axes. - said drilling tool has an axial stem and an abrasive front surface, - said axial stem also has an abrasive surface, having however a grain size smaller than that of the front surface of the drilling tool, said axial stem being adapted to be engaged against the surface of the hole in the glass plate after that the hole has been obtained, in order to enlarge the diameter of the hole, - said abrasive front surface has a substantially spherical shape, - said control device (105, 106, 107, 109, E) includes an electronic control unit programmed for imparting the drilling tool with a pulsed axial movement through the glass plate, comprising a succession of forward movements alternated with stops and/or rearward movements, and in that said device is an electronically controlled machining center comprising: - a work surface, - a working head movable along three mutually orthogonal directions (X, Y, Z) above the work surface, - a motorized spindle provided on the work head and carrying said drilling tool, for rotating the drilling tool around its axis, and - an electronic control unit which can be programmed for controlling the movements of the working head along said three orthogonal axes (X, Y, Z), - said device being further characterized in that said axial movement of the drilling tool is obtained by movement of said working head along one of said three orthogonal axes (X, Y, Z,) and the planetary movement of the drilling tool is obtained by coordinated movements of the working head along the remaining two axes (X, Y) of said three orthogonal axes.