To provide an apparatus for continuously producing a grafted base material in high efficiency.

The apparatus for producing the grafted base material applies a radical-polymerizable compound solution to a base material such as a textile cloth, a sheet material such as paper or film or fibrous base material, sandwiches the base material with films, presses with a nip roll having adjustable pressure to cause close contact of the films to the base material, applies electron beams and accelerates the polymerization reaction in a post-polymerization zone.