[Problem] To provide a milking machine for preventing breast milk leaking from a milking portion undergoing diameter expansion during milking and a negative pressure loss caused by the leak. [Solution] The milking machine of the present invention comprises: an accommodating vessel (11) collecting breast milk; a milking machine main body creating a negative pressure for milking; a milking diameter expansion portion (22) undergoing diameter expansion to come into contact with a breast; and a buffer portion (70) having an almost circular wrapper shape along an opening of the milking diameter expansion portion, at least a portion of which comes into contact with the breast. The buffer portion comprises a contact portion which comes into contact with an areola; a sticking portion which sticks to the breast, etc.
