SOLID-STATE BATTERY

A solid-state battery that includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer between the positive electrode layer and the negative electrode layer, in which the positive electrode layer contains a positive electrode active material and an oxide having a garnet-type crystal structure, and a first Li concentration in an interface vicinity with the positive electrode active material in the oxide is lower than a second Li concentration in a particle interior of the oxide.