A breastshield unit for use with a breastpump for expressing human breastmilk using underpressure has a dimensionally stable breastshield and a flexible breastshield insert for placing in the breastshield. The breastshield has a first, open breastshield end for placing on a mother's breast. The breastshield insert has a first insert end and a second insert end which define a longitudinal direction, the first, open breastshield end having a peripheral edge on which the breastshield insert is securable with the first insert end. In the assembled state, the breastshield insert extends from this first insert end through the inside of the breastshield to the second insert end, wherein the breastshield insert, between the first and second insert ends, extends substantially spaced apart from the breastshield. In the assembled state of the breastshield insert, the second insert end is displaceable in the longitudinal direction relative to the breastshield. The breastshield unit adapts optimally to the shape of the mother's breast and optimizes the bearing force.
