An elastomer membrane based, regulated drip emitter unit, equipped with a non-drip valve, wherein the drip emitter is characterized by that it includes an opening that is exposable to an approximate atmospheric pressure that prevails on the water outlet from the drip emitter; and an additional elastomer membrane portion that is strained and biased against the water inlet opening of the drip emitter for creating a seal with its one side for a non-drain valve and on its other (second) side it is connected to that atmospheric pressure prevailing opening, and wherein the elastomer membrane portion is movable towards that opening in order to open the water inlet opening for enabling a water flow passage from a water supply conduit to the drip emitter, and this from the specific instant that the force exerted by the water pressure prevailing in the water supply conduit on one side of that elastomer portion, overcomes the strain at which that portion was strained and biased against the water inlet opening, as well as the approximate atmospheric pressure that prevails on the other side of that elastomer portion.