To manufacture a sheet for a structural material by an extremely simple method even in the case of a high output by charging a molten resin web at an outside with respect to a structural material forming roll in a supply area of the roll, and connecting the roll as a counterelectrode.

A molten resin web 3 is charged on its outer surface to a structural material forming roll 4 by static electricity in a supply area of the roll 4 by using a corona discharging unit 7. The roll 4 is connected as a counterelectrode in relation to the unit 7. A protruding structural portion of the roll 4 by a recess surface structure 6 is formed by an attraction force due to the static electricity. A protruding structural portion 5 of a sheet 1 for a structural material is formed on the roll 4 by cooling in response to the surface structure 6 of the roll 4.