A main object of the present disclosure is to provide an all solid state battery with excellent capacity durability when restraining pressure is not applied or even when low restraining pressure is applied thereto. The present disclosure achieves the object by providing an all solid state battery comprising layers in the order of a cathode layer, a solid electrolyte layer, and an anode layer; wherein the anode layer contains an anode active material including a silicon clathrate II type crystal phase; restraining pressure of 0 MPa or more and less than 5 MPa is applied to the all solid state battery in a layering direction; and a specific surface area of the anode active material is 8 m2/g or more and 17 m2/g or less.