A breast pump for manually sucking milk from a breast. The pump includes two portions, a first closed top and open bottom portion with the top having an opening and a second portion being open top and closed bottom with a side wall having an opening. A breast shield comprising a funnel-like member for fitting over a breast and a tubular member extending through the top opening of the first member, the tubular member having a predetermined length and extending into the second open-ended portion and including a valve means opening when the portions are pulled apart and closing when the portions are pushed together; the second portion including conduit means connected to the opening in the side wall, the conduit means include valve means closing when the portions are pulled apart and opening when the portions are pushed together, thereby when the elements described above are connected in hooked-up sliding engagement, the liquid extracted may flow through the portions and out the conduit means. Means are provided for keying sliding movement of the portions.