A microscope includes a condenser lens that is arranged removably and insertably with respect to a light path of light from a light source, and an objective that collects the light from the light source, which has been transmitted through a sample. A conditional expression below is satisfied when b is an exit pupil diameter of the objective and adet is a diameter of an area in a state in which the condenser lens has been removed from the light path, the area being included in an exit pupil plane of the objective and being an area through which the light from the light source, which has entered the objective through one point on the sample, passes: 1/20≦adet/b≦1/2   (1).