A dispensing device for dispensing liquids from flexible packaging, in particular for dispensing a defined amount of a liquid from a flexible packaging in the form of pouches or bags of plastic material, which device comprising a device body having generally elongated shape, wherein in said body at its one end, an inlet fitting with an inlet opening is mounted and at its another end an outlet fitting with an outlet opening is mounted, preferably said inlet fitting and outlet fittings are arranged opposite each other, wherein the body defines an inner space of the body, preferably in the form of an internal central opening and said body is further provided on its side surface with a connection opening being in fluid communication with said central opening, wherein to said connection opening, and preferably to a flange outwardly projecting from a side surface of the body and surrounding said connecting opening a resilient bellows is attached in a sealed manner with its open end side, which resilient bellows has generally cylindrical shape and consists of a certain number of folds, preferably in the form of helical coils, that folds are positioned along longitudinal extension of said bellows and wherein said resilient bellows defines inside an inner space of said bellows which inner space is in fluid communication with said connection opening of the body, while opposite end of said resilient bellows being closed with the bottom and wherein said folds or helical coils of resilient bellows are adapted to flex under pressure exerted on said bottom thereof in axial direction of said bellows, towards the body, characterized in that: said dispensing device is further provided with an assembly for stepless adjustment of a volume of dispensed liquid, wherein said assembly for stepless adjustment comprises a control element cooperating with said resilient bellows and arranged on outer side surface of said bellows and/or said flange around their outer periphery, at least on a certain section of a length of said resilient bellows and/or said flange, and further said control element is shaped in the form of an adjusting nut and is provided with marks indicating an adjustable volume of a liquid to be dispensed, and wherein said stepless adjustment of a volume of dispensed liquid is performed by means of: stepless setting up a volume of said inner space of said resilient bellows, wherein said stepless setting can be performed for each, individual action of dispensing of a liquid. said dispensing device is further provided with an assembly for stepless adjustment of a volume of dispensed liquid, wherein said assembly for stepless adjustment comprises a control element cooperating with said resilient bellows and arranged on outer side surface of said bellows and/or said flange around their outer periphery, at least on a certain section of a length of said resilient bellows and/or said flange, and further said control element is shaped in the form of an adjusting nut and is provided with marks indicating an adjustable volume of a liquid to be dispensed, and wherein said stepless adjustment of a volume of dispensed liquid is performed by means of: stepless setting up a volume of said inner space of said resilient bellows, wherein said stepless setting can be performed for each, individual action of dispensing of a liquid.