An automatic system for continuously fabricating Langmuir-Blodgett (LB) films will be described, in which a monolayer on an air-water interface is compressed distributively underneath by a steady laminar flow subphase. The main features of this system are the following. (1) Homogeneous compression to monolayers with a very high surface viscosity, such as polymeric monolayers, can be obtained. (2) Continuous deposition of LB films on a substrate with a large area can be made. The experimental result with the atomic force microscope shows that polymeric chains in a monolayer can be straightened on the flowing water surface. The system is particularly useful in industrial applications for the fabrication of a large quantity of LB films.