An all-solid secondary battery includes a cathode layer; an anode layer; and a solid electrolyte layer disposed between the cathode layer and the anode layer. The cathode layer includes a cathode current collector and a cathode active material layer disposed on the cathode current collector, the anode layer includes an anode current collector and a first anode active material layer disposed on the anode current collector, the cathode active material layer includes a porous oxide-based composite solid electrolyte, and the solid electrolyte layer includes a sulfide-based solid electrolyte.