A scanning near-field optical microscope (SNOM) combined with a scanning tunneling microscope (STM) is used to investigate nanoscopic optical phenomena both in the near-field region and in the proximity. The system is realized by introducing a doubly metal-coated optical fiber tip with an extremely small aperture, on which metal-coating is performed to obtain a half-transparent conducting tip. A simultaneous SNOM/STM observation is performed for an Au (111) surface, where the evanescent field standing on the tip vicinity through the aperture is scattered by the local structures of the sample and the far-field component of the scattered light is collected as an optical signal. The distance con-trol is carried out under constant current condition in order to separate the optical properties from surface topography. λ/100 optical resolution and the identical channel transport both for electrons and photons are achieved.