A capacitive electrical machine with tensioned electrodes relates to the broad class of transformers for converting electrical energy into mechanical energy and vice versa by means of the electrostatic forces of Coulomb attraction between opposite charges. Capacitive electrical machines can be used in industry and engineering as electric motors and generators in a very broad range of fields. In order to increase the power of a capacitive electrical machine, the present invention proposes using electrodes in the form of strips or films or thin wires in a state of constant tension, which are fastened in such a state in the structure of the capacitive electrical machine, thus making it possible to house a large number of interacting plane parallel electrodes in a limited space. The solutions claimed in the present invention achieve the technical results of an increase in power and specific power and an improvement in other power characteristics of electrostatic transformers, i.e. capacitive electrical machines.