A confocal probe is provided with an optical fiber introducing light having wavelengths within a predetermined wavelength range in the confocal probe, a collimating lens that collimates light emerged from an end surface of the optical fiber, a dispersing prism that receives the light collimated by the collimating lens and disperses the received light in a predetermined direction, light emerged from the dispersing prism and having the same wavelength being kept collimated, and a light converging optical system that converges the light emerged from the dispersing prism on a target (i.e., region of interest).