Ion thruster comprising: - a chamber, - a tank comprising a solid propellant, said tank comprising a conductive jacket provided with at least one orifice; - a set of means (30, 30', 40) for forming an ion-electron plasma in the chamber, said set being able to sublime the solid propellant in the tank in order to form a propellant in the gaseous state, then to generate said plasma in the chamber from the propellant in the gaseous state coming from the tank through said at least one orifice; - a means for extracting and accelerating at least the ions of the plasma out of the chamber, said means for extracting and accelerating comprising: • either an electrode housed in the chamber to which is associated a grid located at one end of the chamber, said electrode having a surface that is greater than the surface of the grid, • or a set of at least two grids (52', 51) located at one end of the chamber; - a DC voltage source (30") or a radiofrequency AC voltage source arranged in series with a capacitor and adapted for generating a signal of which the radiofrequency is between the plasma frequency of the ions and the plasma frequency of the electrons, said DC (30") or radiofrequency AC voltage source being connected, by one of its outputs, to the means for extracting and accelerating at least the ions of the plasma out of the chamber, and more precisely: • either to the electrode, • or to one of the grids of said set of at least two grids (51, 52'), with the grid associated with the electrode or, according to the case, the other grid of said set of at least two grids (52', 51) being either set to a reference potential, or connected to the other of the outputs of said radiofrequency AC voltage source; said means for extracting and accelerating and said DC or radiofrequency AC voltage source (30, 30") making it possible to form, at the output of the chamber, a beam (70, 70') comprising at least ions; characterised in that said tank is housed in the chamber. - a chamber, - a tank comprising a solid propellant, said tank comprising a conductive jacket provided with at least one orifice; - a set of means (30, 30', 40) for forming an ion-electron plasma in the chamber, said set being able to sublime the solid propellant in the tank in order to form a propellant in the gaseous state, then to generate said plasma in the chamber from the propellant in the gaseous state coming from the tank through said at least one orifice; - a means for extracting and accelerating at least the ions of the plasma out of the chamber, said means for extracting and accelerating comprising: • either an electrode housed in the chamber to which is associated a grid located at one end of the chamber, said electrode having a surface that is greater than the surface of the grid, • or a set of at least two grids (52', 51) located at one end of the chamber; • either an electrode housed in the chamber to which is associated a grid located at one end of the chamber, said electrode having a surface that is greater than the surface of the grid, • or a set of at least two grids (52', 51) located at one end of the chamber; - a DC voltage source (30") or a radiofrequency AC voltage source arranged in series with a capacitor and adapted for generating a signal of which the radiofrequency is between the plasma frequency of the ions and the plasma frequency of the electrons, said DC (30") or radiofrequency AC voltage source being connected, by one of its outputs, to the means for extracting and accelerating at least the ions of the plasma out of the chamber, and more precisely: • either to the electrode, • or to one of the grids of said set of at least two grids (51, 52'), • either to the electrode, • or to one of the grids of said set of at least two grids (51, 52'),