To provide a surface protective film for an adhesive resin capable of being easily released from the surface of the adhesive resin to be adapted, not almost containing a residual organic solvent or a plasticizer, which exerts adverse affect on the adhesiveness of the adhesive resin itself, having excellent surface smoothness itself and causing no occurrence of a fish-eye or thickness irregularity, and its manufacturing method.

In the surface protective film for the adhesive resin obtained by laminating a polysulfone resin layer (B) on at least one side of a base material film (A), the polysulfone resin layer (B) is formed from a polysulfone resin solution composition prepared by dissolving at least one kind of a polysulfone resin in a mixed solvent composed of at least one of lactones (a) and aromatic ketones (b), a cyclic ketones (c) and an aliphatic ketone with a boiling point of 150°C or below.