Patent attributes
An observation field of view of a microscope can be moved without moving or changing an objective lens and without varying position or state of a sample. A microscope optical system has a mirror that changes the direction of the optical path by reflection. The mirror is located in the optical path between an objective lens of the microscope and an image to be observed. The mirror can be tilted to change the position of a reflecting surface of the mirror. Accordingly, the observation field of view is moved by tilting the mirror without changing a positional relation between the objective lens of the microscope and the sample.