A liquid droplet spray device for ejecting a liquid as a spray of droplets has a cartridge (15) with a nozzle arrangement (13) to eject droplets, which is vibrated by a piezo element (23a) through the agency of an actuating element (23). A resonance chamber is disposed between an inner wall (15a) of the cartridge and the actuating element (23) such that the cartridge inner wall (15a) is separated by a gap having a length B from the actuating element (23), the cartridge inner wall (15a) being cap-shaped and extending along the side surfaces of the actuating element (23) and being frictionally attached to the side surfaces along a distance A. The resonance chamber (10) improves the efficiency of transmission of vibrations to the cartridge.