Disclosed is a coating agent including a synthetic resin emulsion (A) wherein an acrylic resin of which the main monomer component is an alkyl ester of (meth)acrylic acid, and a silicone resin of which the main monomer component is a cyclic siloxane compound are mixed in emulsion particles to set the ratio by weight of the former to the latter into the range of 99/1 to 30/70, and a particulate matter (B) having an average particle diameter of 0.5 to 500 .mu.m and an oil absorption of 60 mL/100 g or less, wherein the particulate matter (B) has a pigment volume concentration of 10 to 90%. When this coating agent is stored or after a paint film is made therefrom, a fall in the water repellent effect thereof is restrained, so that an excellent water repellent performance can stably be exhibited.