A confocal microscope apparatus includes an image acquisition unit configured to obtain a first all-in-focus image of each of a plurality of measurement visual field areas constituting a measurement target area in a brightness setting in accordance with the corresponding measurement visual field area, and a stitched image constructor configured to construct a stitched image on the basis of a plurality of second all-in-focus images. The second all-in-focus images are obtained through conversion of the plurality of first all-in-focus images obtained by the image acquisition unit so that the images become closer to a plurality of reference all-in-focus images. The plurality of reference all-in-focus images are obtained when the plurality of measurement visual field area are captured in a brightness setting serving as a reference.