Provided is a plastic thin film material, on which a process material can be applied or deposited at low cost and with high efficiency, and in which an inorganic substance powder capable of achieving a functional processing for enabling the strong adhesion of a laminated layer on the thin film material is filled at a high density. A thin film material for processing use, which contains a thermoplastic resin and an inorganic substance powder at a weight ratio of 18:82 to 50:50, and has a specific gravity of 0.60 to 1.40 inclusive and a degree of absorption of water of 0.0 to 11.0 g/m2·120 sec inclusive as measured by a Cobb method in accordance with JIS P 8140.