Microscope

A microscope includes an observation optical unit that has a zoom optical system having variable zoom power and an objective lens optically connected to the zoom optical system, the observation optical unit receiving observation light emitted from an observation sample, a focusing unit that has a focusing mechanism to focus the observation optical unit on the observation sample, a light source unit that emits illuminating light to illuminate the observation sample, and an illuminating unit that has a reflecting optical element disposed in the observation optical unit but out of an optical path of the zoom optical system, the illuminating unit being partially disposed in the focusing unit, the illuminating unit illuminating the observation sample with the illuminating light via the reflecting optical element and the objective lens.