In this paper, we review the dynamic contact angle measurements by Wilhelmy method as one of the powerful tools for surface characterization. The dynamic contact angle measurements enable us to characterize not only simple wettability but also various surface-related phenomena, such as surface stability, topochemical structures, dynamic movement of adsorbed molecules on surfaces, etc. Especially, combination with scanning probe microscope (SPM) techniques for microscopic survey of surfaces provides clear and reliable understandings of features of monolayer surfaces. As examples of the performance, we introduce three typical studies with monomolecular films; 1) dimethyldioctadecyl ammonium bromide Langmuir-Blodgett (LB) monolayers on cleaved mica, 2) dioctadecyl sulfide self-assembled monolayer (SAM) on gold, and 3) unsymmetrical azobenzene disulfide SAMs designed for surface photo reactions. Different responses in the contact angle measurements on the surfaces revealed unique film properties. New ideas for the experiment or data analysis are also introduced.