We report on the near-field imaging of silver nanoparticles using an aperture-type near-field microscope operated in illumination mode. The nanoparticles are imaged as interference patterns, due to far-field superposition of the optical fields emitted from the tip and elastically scattered from localized surface plasmons (SP). Aperture-type probe can thus be used to obtain information on the phase shift associated with localized SP coupling at the illumination wavelength. (C) 2002 American Institute of Physics.