The present invention provides an optical member comprising a silicone material having excellent antifouling property while having good light transmittance, heat resistance, and strength, and an optical semiconductor device and illumination apparatus having excellent antifouling property. The present invention is an optical member comprising a silicone material containing a fluorinated surface, the proportion of F atoms being from 0.1 to 45 at % and/or the ratio of F atoms relative to C atoms being from 0.01 to 1.00 in the atomic composition percentage according to X-ray photoelectron spectroscopy (XPS) of the fluorinated surface.