In order to confirm the application possibility to the molecular electronic device, the morphological property of arachidic acid (AA) was investigated. We have determined morphology by BAM and AFM. pi-A curves investigated surface pressure of this LB film from liquid to solid state ranged between 40 to 45mN/m. BAM images investigated the different states of AA LB film. When the surface pressure reaches at 40mN/m, the monolayer was deposited onto the hydrophilic glass substrates by Y-type deposition. We investigated morphological property of arachidic acid by AFM. As a result, we obtained the frequency characteristic and morphology of LB films from controlling the deposited layers. In this paper, I review this subject mainly based on our recent results in merocyanine dye. LB films of merocyanine dye, mixed with arachidic acid, exhibit J-aggregate formation and have been serving as typical systems in revealing the physical and structural aspects of nano-sized molecular aggregates constructed as muiltilayers.