A manual breast pump, including a housing; a funnel connected to the housing and forming a passage for breast milk; a cup for receiving a breast; a lid connected to an upper portion of the housing; a handle assembly connected to the lid; a substantially semi-circular finger grip connected to the housing; a piston movably connected to the handle assembly and reciprocally movable within the housing to create a negative pressure for the expression of breast milk from the breast; a flexible insert sealably secured to the cup and forming an isolated air volume between the cup and the flexible insert. A valve is removably connected to a lower portion of the housing; and a receptacle for receiving the breast milk, the receptacle being removably attached to a lower portion of the housing. The isolated air volume expands and contracts as the piston moves reciprocally within the housing, causing the flexible insert to move.