PURPOSE: To provide a transmission electron microscope aperture high in accuracy and in the freedom of an opening part shape.

CONSTITUTION: This aperture is provided with at least two layers of a supporting layer 101, ensuring mechanical strength, and an electron beam preventing layer 103 preventing the transmission of an electron beam, and an opening part 104, etc., transmitting an electron beam, is provided on the electron beam preventing layer 103 and the supporting layer 101. Since the thickness of the electron beam preventing layer can be thinned by this two-layer structure, improving the work accuracy of the opening part. The opening part of the supporting layer can be formed in self alignment by using a material, which can not be etched with an etching agent for the supporting layer, for the electron beam preventing layer.