To provide: a workpiece with which a desired pattern such as, for example, a wiring pattern is formed without causing the deterioration of a substrate even for a substrate like a plastic film having a low heat resistance; and a method for producing the workpiece.

This method for producing the workpiece includes the steps of: coating a coating material, which contains nanoparticles covered with a dispersant, on a substrate; and separating the covering dispersant from the surface of each nanoparticle at a low temperature range by performing plasma treatment to the coating material coated on the substrate, and promoting sintering between particles.