The disclosure provides an electrode for solid state battery, a solid state battery, and a manufacturing method of the electrode for solid state battery. The electrode for solid state battery uses a foamed porous body as the collector. When the electrode constitutes the solid state battery, the obtained battery has low resistance, high battery capacity per unit area, and high output. A collector composed of a foamed porous body is filled with an electrode mixture by differential pressure filling to obtain an electrode, in which the content rate of an organic polymer compound is low.