Provided are a binder in the producing of a casting sand mold according to an ink jet type lamination shaping method in which a binder is printed with respect to sand, a method for producing the binder, and a method for producing a casting sand mold using the binder. Specifically, provided are a binder useful for a casting sand mold of an ink jet type, containing: a resol-type phenolic resin that is obtained by reacting aldehydes (A1), phenols (P1), and a compound (N) having two or more phenolic hydroxyl groups in one molecule or by reacting the aldehydes (A1) and a novolac-type phenolic resin (N1), in the presence of an alkali catalyst, and has a dispersion degree (Mw/Mn) of 1.0 to 3.5 and a phenolic monomer residue of 5% or less, a method for producing the binder, and a method for producing a casting sand mold.