Patent ID: 7749188

Claim:
A breast pump, comprising: a housing container for storing expressed milk; a first attachment and detachment part configured to detachably attach a breast pump body to the housing container; a negative pressure generating member attached to the breast pump body; and an operation unit which is attached to the breast pump body and deforms the negative pressure generating member, wherein the breast pump body includes: a milking part which is diameter-expanded toward its leading end, with which a user's breast comes into contact, a valve chamber arranged to face the housing container and contacting the diameter-expanded milking part, and an attachment part contacting the valve chamber and attaching to the negative pressure generating member that creates a negative pressure necessary to express milk; and the negative pressure generating member includes: a connector to which the operation unit is connected, a second attachment and detachment part formed of comparatively soft material having elasticity and attached detachably to the attachment part of the breast pump body, a wall part provided integrally for the second attachment and detachment part and having such rigidity that an external shape can be kept, and a deformable part, which is provided on the inside of the wall part integrally with the wall part, is smaller in thickness than the wall part, and deforms upon receiving a force from the connector thereby to create the negative pressure, wherein the wall part of the negative pressure generating member is cylindrical and extends upright, an upper end portion of the cylindrical wall part being turned down inwardly to define the deformable part, wherein a wall space is defined between the deformable part and the wall part along an entire length of the deformable wall, the wall space having an upper boundary defined by an upper end part of the wall part and having a lower boundary defined by the attachment part, and wherein the attachment part does not contact the upper end portion of the wall part.