An ``x-ray microscope'' which can take both x-ray diffraction patterns and magnified Laue-diffraction images of selected areas of the specimen under microscopic observation has been constructed. Resolving power of the microscope is 0.3 μ and the minimum diameter of the selected area of the specimen is about 10 μ. A decontamination device for the target is incorporated into the instrument. Some applications of the methods of x-ray microscopy, selected-area diffraction, and magnified Laue diffraction are described. It is shown that the selected-area diffraction patterns are useful for the identification of the components of the specimen with complicated structure. It is also shown that the magnified Laue-diffraction images are useful for the study of imperfections and local distortions in crystals.