A phase contrast transmission electron microscope apparatus has a long-life phase modulator, enabling changes in quantity of phase modulation, barely absorbing the electron beams, and not being influenced by irradiation of the electron beams. An electron microscope comprises an electron gun, a first laser beam irradiating process, being positioned between the electron source and an object lens, for irradiating laser beams onto the electron beams radiated from the electron gun, a second laser beam irradiating process, being positioned on a focal plane behind the object lens, for focusing and irradiating the laser beams upon the focus of the electron beams penetrating through a specimen, and a screen or a 2D electron sensor for detecting a specimen image in the form of distribution of intensity of the electron beams by an optical system.