The invention provides an electrical power module, including power transistors, and control components for controlling said power transistors, said module being cooled, in particular, by heat conduction. The module of the invention further includes a main substrate of the AMB/Si3N4 type carrying the power transistors, this main substrate itself constituting a heat-dissipating baseplate for dissipating the heat generated by the power transistors by being arranged in the module to be directly in contact with the carrier structure that provides cooling by conduction when said module is in place, and a ceramic substrate carrying the control components, this ceramic substrate itself being carried by the main substrate.