INVERTED MICROSCOPE

PROBLEM TO BE SOLVED: To provide an inverted microscope into which various auxiliary apparatus applicable to inverted microscopes for industrial applications having vertical illumination can be built and which are low in terms of a cost and is excellent in operability. SOLUTION: This inverted microscope has an objective lens (10) which is arranged on the lower side of a sample, an imagery lens (12) which is arranged in the optical path of the observation light emitted from the objective lens and images the observation light, a vertical illuminating optical system (9) which is arranged between the objective lens and the imagery lens and introduces the vertical illumination to the optical path of the observation light and an input/output port (25) which is arranged between the vertical illuminating optical system and the imagery lens and branches the luminous flux from the optical path of observation light and introduces the luminous flux to the optical path of the observation light.