A microscope apparatus 10 includes a detection optical system 12 that captures light from a sample S and an illumination optical system 11 that radiates an illumination light onto the sample S. The illumination optical system 11 includes a cylindrical lens 5 that has a power in a first-axis direction and does not have a power in a second-axis direction that is perpendicular to the first-axis direction, a cylindrical lens 6 that has a power in the second-axis direction and does not have a power in the first-axis direction, and a scanner 4 that scans the illumination light in a width direction. The illumination optical system 11 is configured such that the first-axis direction is the width direction described above, and the cylindrical lenses 5 and 6 are arranged posterior to the scanner 4.