Abstract: A manually operated ejector device for containing a cartridge loaded with viscous material, having a chamber with a front end adapted to contain the cartridge and a back end, a piston disposed in the chamber for engagement in the cartridge, a handle arranged at the back end of the chamber, and a lever displaceable relative to the chamber and the handle for driving the piston in order to drive the latter in its longitudinal direction toward the front end of the chamber. To improve the safety of the handling of the ejector device, the piston has a spring case and a plunger, the spring case having a chamber whose one end is closed and whose other, front end has an opening, the transition between the chamber and the opening being limited by an abutment surface facing the chamber.