An electron microscope according to the present invention includes a phase plate (510) having a thickness which changes in a radial direction, and adjusts a phase difference caused by a difference in electron beam path due to an effect of a spherical aberration when an electron beam is converged by a lens or an image of the electron beam is formed. Accordingly, the phase difference caused by the difference in electron beam path is adjusted, to thereby improve the coherence, so that a phase contrast image of transmitted electrons can be obtained at a higher resolution.