Abstract: A source of fast neutral molecules comprises a gas discharge chamber (1) with an anode (5), a cathode (7) and a gas discharge power supply (8), a charge transfer chamber (2) with additional electrodes (16), an accelerating grid (3) composed of grid elements (18) isolated electrically from each other and an accelerating voltage power supply (4). The width of the accelerating grid (3) exceeds within the ion-producing gas pressure range the ion charge transfer length L=1/n&sgr;, n being gas molecule density and &sgr; being charge transfer collision cross-section. The negative pole of the accelerating voltage power supply (4) is connected through a resistor (11) to the charge transfer chamber (2), through resistors (17) to the additional electrodes (16) and through resistors (19) to the grid elements (18).