To improve adhesion between mutual active material particles, improve capacity of a battery, and obtain stable cycle performance by forming a synthetic resin layer on a surface of an active material particle to constitute at least a negative electrode among a positive electrode and the negative electrode.

Graphitic carbon is used as a negative electrode active material, and a mixture of a paste-like fluororesin and electrolyte is added to and mixed with dried carbon powder, and a graphitic carbon active material particle whose surface is wrapped in a viscous or paste-like fluororesin layer is formed. A mixed liquid by mixing electrolyte and an ethylene oxide monomer is added and mixed. Mixed paste is applied onto Cu foil, and is hardened by EB irradiation. In high polymer solid electrolyte formed by subjecting it to EB irradiation, a cavity of particles is filled up, and a solid-shaped negative electrode is formed. Therefore, a solid electrolyte battery which is excellent in discharge parformance and charge-discharge cycle performance and whose manufacturing process is simplified, can be obtained.