A quantitative analysis method with a low-energy photo-electron counter in the atmosphere was developed for pigment on surface of polymer particles, and the detectable depth of this method for organic compounds was experimentally estimated using LB-film. First, we investigated the changes of photo-electron emission property (i. e. ionization energy and line inclination of emission yield vs. irradiation energy) of aluminum substrate, when the thickness of LB-film on it increased according to the number of arachidic acid monolayers. Thereby the detectable depth was estimated to be less than 90 Af. Next, samples covered with varying amounts of carbon black were prepared for determining the correlation between surface carbon black coverage and photo-electron property. Based on this correlation, surface carbon black concentration on dispersive complex-particles was estimated, and the result was found to be consistent with the observation of the particle surface with SEM.