An electron microscope is provided with a scintillator (7) and a light guide (8). The scintillator (7) has an index of refraction greater than the index of refraction of the light guide (8), and an end surface (72) joined to the light guide (8) is formed from a curved surface with a convex shape on the outside. The scintillator (7) is formed by a Y—Al—O based ceramic sintered body represented by the compositional formula (Ln1-xCex)3M5O12 (wherein Ln represents at least one element selected from the group consisting of Y, Gd, La, and Lu, and M represents either or both of Al and Ga).