The present invention relates to a method for filling a fluid into a container without using measuring means and to a filling apparatus therefor which comprises an attachment having a predetermined volume VA, said attachment comprising a valve attachment which has a gas valve and a liquid valve with a valve seat in a housing. Said valve seat surrounds a displacement element that can be moved along the longitudinal axis relative to the housing, and forms an annular gap. According to said method, the attachment is tightly placed onto a container (1) while the displacement element is inserted into the container (1). When the liquid valve (5) is opened, the filling fluid flows into the nominal volume VN of the container (1), and said nominal volume is flooded with the filling fluid; the liquid valve is then closed. The displacement element is withdrawn from the container (1) and the flooded remaining volumes top up the contents in the container (1), the volumina VVA and VFV equaling the volume VRohr of a portion of the displacement element in the flooded portion so that identical containers (1) are filled with identical fill levels.