Abstract: A feeding bottle (2) having a bottom cap (8) comprising an inverted cup shaped portion (10), which projects into the bottle and is surrounded by a stretched, resilient rubber sleeve (12) covering a radial hole (14) in the cylindric wall of the cup portion (10) to form an automatic air intake valve. The radial hole (14) is provided in a part-cylindric facet (16) of reduced cross section curvature, whereby even a gross rubber sleeve (12) is easily liftable from the hole (14) for sensitively admitting air into the bottle (2) whenever a moderate suction vacuum is built up therein.