Solid electrolyte and secondary battery

The purpose of the present invention is to provide a solid electrolyte which can prevent the penetration of dendrites of electrode components, and has high ion conductivity, and to provide a secondary battery using the electrolyte. A solid electrolyte according to the present invention is sheet-shaped, is formed from an oxide sintered body, and comprises: a layer-shaped compact section having a sintered density of 90% or more; and a porous section which is formed so as to connect with at least one surface of the compact section on the surface-side of the solid electrolyte, and which has a porosity of at least 50%. A secondary battery according to the present invention comprises the solid electrolyte, and a positive electrode and a negative electrode which are arranged at corresponding positions sandwiching the solid electrolyte. Also, a secondary battery according to the present invention comprises: a separator comprising solid electrolyte; the positive electrode and negative electrode which are arranged at corresponding positions sandwiching the separator; and electrolyte solution which is filled in the negative electrode-side where the negative electrode is disposed and/or the positive electrode-side where the positive electrode is disposed, sandwiching the separator.