Milk meter (10) for milking plants comprising an upper collecting chamber (30) delimited at the top by a covering membrane (33), a first discharge opening (22) connectable to a milk passage manifold of a milking plant, said first discharge opening (22) being adapted to put in communication the milk passage manifold with the upper collecting chamber (30), a lower measuring chamber (40) connected to the upper collecting chamber (30) and communicating with it by means of a second discharge opening (32), a shutter (31) comprising a central portion (36), adapted to open and/or close the second discharge opening (32), and an upper portion (37) connected to the central portion (36) and associated with the covering membrane (33), wherein the central portion (36) of the shutter (31) comprises a chimney (51) to discharge upwards, that is towards the upper collecting chamber (30) and towards the first discharge opening (22), the air rising from the lower measuring chamber (40) when the latter chamber becomes filled with milk.