A specific macromolecule crystal evaluating device according to the present invention is equipped with a sample detecting stage for detecting a protein crystal in a sample container, an X-ray measuring stage that is spaced from the sample detecting stage and carries out X-ray diffraction measurement of the protein crystal, a feeding unit for feeding the sample container from the sample detecting stage to the X-ray measuring stage, and a central processing unit for recognizing the position of the protein crystal on the basis of the information achieved in the sample detecting stage and controlling the feeding unit on the basis of the position information to position the protein crystal to a sample disposing portion of the X-ray measuring stage.