The all-solid battery has two electrode layers of a positive electrode and a negative electrode interposing a solid electrolyte layer therebetween, in which at least one of the electrode layers is composed of a sintered body of a mixed material including at least one or more types of electrode active material particles comprising electrode active material and solid electrolyte particles comprising solid electrolyte, and a portion of at least 30% by area of a grain boundary surrounding the electrode active material particles has a coating layer with a thickness of 1 to 200 nm.