Provided is a laser scanning microscope having a first focusing-position control unit (15) and a confocal detecting unit (24,25). The first focusing-position control unit (15) shifts a first focusing position of a laser beam on a sample (20) in a direction of an optical axis of an objective lens (19). The confocal detecting unit (24,25) has a confocal aperture (24) for a confocal detection of a light emitted from the first focusing position. The microscope may include a second focusing-position control unit (21) shifting a second focusing position of the light emitted from the first focusing position focused by the confocal detecting unit (24,25) in a direction of an optical path thereof.