Provided are: an addition polymer of fluorosilsesquioxane (a) having one addition polymerizable functional group or an addition copolymer of the fluorosilsesquioxane (a) having one addition polymerizable functional group and an addition polymerizable monomer (b); a coating film including the polymer or the copolymer; and an addition copolymer of the fluorosilsesquioxane (a) having one addition polymerizable functional group and organopolysiloxane (c) having an addition polymerizable functional group, or an addition copolymer of the fluorosilsesquioxane (a) having one addition polymerizable functional group, the organopolysiloxane (c) having an addition polymerizable functional group, and the addition polymerizable monomer (b).