Electron scanning microscope and image generation method

In a scanning electron microscope, an atmospheric pressure space having a specimen arranged therein and a vacuum space arranged on a charged particle optical system side are isolated from each other using an isolation film that transmits charged particle beams. The scanning electron microscope has an electron optical lens barrel, a chassis, and an isolation film. The electron optical lens barrel radiates a primary electron beam onto a specimen. The chassis is directly bonded to the inside of the electron optical lens barrel and has an inside that turns into a lower vacuum state than the inside of the electron optical lens barrel at least during the radiation of the primary electron beam. The isolation film isolates a space in an atmospheric pressure atmosphere having a specimen mounted therein and the inside of the chassis in a lower vacuum state, and transmits the primary charged particle beam.