A silsesquioxane resin, a positive resist composition, a resist laminate, and a method of forming a resist pattern that are capable of suppressing a degas phenomenon are provided, and a silicon-containing resist composition and a method of forming a resist pattern that are ideally suited to immersion lithography are also provided. The silsesquioxane resin includes structural units represented by the general shown below [wherein, R1 and R2 each represent, independently, a straight chain, branched, or cyclic saturated aliphatic hydrocarbon group; R3 represents an acid dissociable, dissolution inhibiting group containing a hydrocarbon group that includes an aliphatic monocyclic or polycyclic group; R4 represents a hydrogen atom, or a straight chain, branched, or cyclic alkyl group; X represents an alkyl group of 1 to 8 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom; and m represents an integer from 1 to 3].