A scanning optical microscope including: a light source; a lens for altering the cross-sectional shape aspect ratio of a beam of light emitted from the light source; at least one lens for converging beams of light of different cross-sectional shape aspect ratio to create a linear light; a first light modulation member able to impart shade to the converged linear light; a lens that can form the light to which the shade has been imparted as a parallel light; a scanning member that can alter the angle of illumination; a lens for focusing the light to which the shade has been imparted; an objective lens for projecting the light to which the shading has been imparted to a sample body; and a lens for imaging the reflected light from the sample body or the light generated by the sample body on to a sensor.