A level measurement device for measuring a level (L) of a product, in particular a product contained in a container, comprising: mounting means for mounting said measurement device at a measurement site, an antenna comprising a dielectric antenna element for transmitting microwave signals (S) towards the product and/or for receiving echo signals (R) resulting from reflections of the transmitted microwave signals, and measurement electronics for determining the level (L) of the product based on a transit time needed for the microwave signals to travel to a surface of the product and of their echo signals to return to the device, is described allowing to prevent deposits to build up, which may eventually impair transmission and/or reception of the signals. To this extent, the measurement device according to the invention comprises a cap covering said dielectric antenna element and cleaning means for cleaning said cap are foreseen, which cause said cap to vibrate when they are activated.