PURPOSE: To measure and display a wide range of two-dimentional distribution of inclusions in a steel sample by applying a electron beam selected within the limit of 0.1W10mm in diameter to the steel sample in a vacuum.

CONSTITUTION: Electron beam EB is applied to the surface of a sample 5, and X- rays radiated from the sample 5 is spread by an X-ray spectroscope 7c having a plane crystal 30 and an X-ray detector 31. The electron beam EB excites inclusions 33 such as Fe, S, or P in the sample 5, and generates characteristic X-rays, Fe-Ka and S-Ka, which are detected by spectroscopes 7e and 7c respectively. The spectroscope 7c is for elementary analysis of the inclusions 33, and the spectroscope 7e is for detecting a crack 37. The electron beam EB permits informations about the inclusions 33 and the crack 37 to be obtained, with the sample 5 moved in the directions of X and Y. The constitution eliminates the need for griding the surface of an object under test having a wide area. Moreover, the distribution pattern of the inclusions can be directly measured, and the crack pattern can be detected also.