Abstract: The invention represents an evaporation and/or precipitation measuring equipment, which can measure with high-accuracy, continuously and automatically the evaporation of an open water surface and simultaneously eventual precipitation. The value of evaporation, which is defined as the decrease of the water level of a standard evaporation measuring vat, is measured by the equipment with the quantity of water necessary to compensate the original level. Precipitation on the other hand is measured with that quantity of water which needs to be let out in order to restore the original water level of the vat. The high accuracy can be obtained on the one hand by adjusting deliberately small feeding resp. lower quantities. On the other hand the sensing unit of the equipment watches the water level of the evaporation measuring vat with high accuracy, and controls the supply and lower units respectively when the level varies due to either evaporation or precipitation.