The present paper describes the applicability of atomic force microscopy (AFM) to the observation of living cultured cells of an epithelial nature (human esophageal squamous cell carcinoma cells, or C7 subclone of KESC2 cells) in a culture medium. For this purpose, we made a fluid chamber system which allows a constant-speed perfusion of fluid at a regulated temperature in the chamber. Using this system, AFM images of living cells were successfully obtained for over one hour at time intervals of 2-4 min during continuous perfusion of the fresh culture medium. A series of these AFM images proved useful for examining the movements of cellular processes in relation to subcellular cytoskeletal elements. Time-lapse movie records produced by sequential AFM images further verify the reality of the cellular dynamics.