Microscope apparatus automatically changes illumination according to various observation methods

A microscope apparatus includes: a light source configured to emit illumination light to illuminate a specimen; a dimming input unit configured to set and input a light amount of the light source in a predetermined dimming range; a switching unit configured to switch a first instruction value instructing the light amount of the light source to a second instruction value larger than the first instruction value when a switching signal to switch the light amount of the light source is input; and a control unit configured to control a light amount of the illumination light emitted from the light source according to the first instruction value set and input by the dimming input unit or the second instruction value obtained by switching by the switching unit.