Patent ID: 8773758

Claim:
A microscope apparatus comprising: an illumination optical system that is configured to irradiate a sample including a plurality of fluorescent materials with activation light and excitation light so as to activate and excite a portion of the plurality of fluorescent materials; an imaging optical system that is configured to receive fluorescence, which is emitted from a portion of the plurality of fluorescent materials, through an objective lens and to form an image to which an astigmatic difference is given; an imaging device that is configured to capture the image to which the astigmatic difference is given; a control unit that is configured to control the illumination optical system to irradiate the sample with the activation light and the excitation light repeatedly, and to determine a three-dimensional position which is x-, y-, and z-positions of the plurality of fluorescent materials on the basis of a plurality of images which are obtained by capturing images to each of which the astigmatic difference is given, and an astigmatic difference changing device so as to change the astigmatic difference, wherein a plurality of objective lenses of which magnification is different from each other are switchably arranged in the imaging optical system, and when one objective lens is switched by another objective lens, the control unit controls the astigmatic difference changing device to change the astigmatic difference according to a depth of focus of the another objective lens.