To lower electrical resistance by increasing the interfacial surface area and the adhesion between a current collector and an active material or an electrolyte, or between the active material and the electrolyte in an all-solid-state battery. In addition, to improve battery performance by eliminating or minimizing residual carbon originating from a binder. A slurry, composed of an electrode active material and a solvent, and a slurry, composed of electrolyte particles and a solvent, can be impacted against a target and thereby attached thereto to form a high-density layer and improve adhesion. Moreover, residual carbon is eliminated or minimized by eliminating or minimizing the content of binders, thereby improving battery performance.