The interaction and adhesive forces between a mica plate and SiO2, surfaces in water-alcohol (ethanol, l-propanol, l-butanol, l-pentanol, 1-hexanol) mixtures were investigated on the molecular scale, using an atomic force microscope. The following results were obtained: (i) alcohols higher than l-propanol adsorb standing on the hydrophilic surface vertically to form a structured monolayer, when the alcohol concentration is high enough; (ii) the adhesive force between surfaces depends on how closely two surfaces can be brought by breaking the adsorbed layers; (iii) the adhesive force between surfaces is maximized at w(w)/w(ws) similar to 0.25, independent of the kind of alcohol, where w(w) and w(ws) are the weight fractions of water and saturated water, respectively; and (iv) the adhesive force for a particle of rough surface is much smaller than the adhesive force predicted for a particle of smooth surface. It is hypothesized that this adhesive force much greater than the van der Waals attractive force originates i om the water bridging between surfaces, and this hypothesis is confirmed by the predictions given by the Laplace equation and the Kelvin relation.