An electric machine having a tangential architecture comprising a rotor, rotating about an axis of rotation, a stator, coaxial to the rotor with respect to said axis of rotation, the stator comprising a casing which at least partially incorporates the rotor, a power supply body which incorporates a controller for the actuation, the power supply and the control of the electric machine. The power supply body is located outside the stator and parallel to the axis of rotation in a position substantially tangent to the casing of the stator. The controller includes a power module to power the electric machine. The power module is provided with a main heat sink, suitable to dissipate the thermal power emitted by the power module itself, and the power module is thermally insulated from the remaining controller.