A breastshield unit for expressing human breastmilk has a receiving part for receiving a human nipple, an underpressure chamber for applying an under-pressure to the nipple, wherein the receiving part opens into this underpressure chamber, and a membrane for generating an underpressure in the underpressure chamber. The membrane is designed in one or more pieces and at least partially surrounds the receiving part. This breastshield unit permits a separation of media in the area near the breast. It is small and easy to clean and is suitable in particular for use as a hands-free breastshield unit.