This device comprises an electrode, the diameter of which is of the same order of magnitude as the drop to be projected, which emerges on the surface of an electrically insulating support. This support is immersed in a reservoir of liquid which comprises an opening. The support is placed so that the face thereof with which the electrode is flush, is located at a certain distance recessed from the plane of the opening so that it is covered with the liquid contained in the reservoir in which is located the counter-electrode. These electrodes are connected to a source of intermittent current designed to form an electric field through the liquid which, by concentrating on that part of the electrode emerging from the support, causes the projection of a drop of liquid.