This invention relates to the means for taking X-ray pictures of the breast. In the present practice of taking such X-ray pictures, it is desirable to apply compression to the breast, the X-ray picture thereby being improved. Various means have been devised, such as a balloon, for the application of the pressure. In U.S. Pat. No. 3,824,397, another such means is shown wherein the pressure is applied to a plastic sheet which is placed on the breast, such means, however, do not provide the application of the pressure uniformly over the entire breast. As a result of applying the pressure irregularly, the image is not improved in all areas of the breast.