A secondary battery according to the present invention includes a first electrode (11), a second electrode (17), a charging layer (14) arranged between the first electrode (11) and the second electrode (17) and containing a mixture of an insulating material and a first n-type oxide semiconductor material, an n-type oxide semiconductor layer (13) arranged between the charging layer (14) and the first electrode (11) and containing a second n-type oxide semiconductor material, a p-type oxide semiconductor layer (16) arranged between the charging layer (14) and the second electrode (17) and containing a p-type oxide semiconductor material, a mixture layer (15) arranged between the charging layer (14) and the p-type oxide semiconductor layer (16) and containing a mixture of silicon oxide and a third n-type oxide semiconductor material, and a conductive layer (12) arranged between the first electrode (11) and the n-type oxide semiconductor layer (13) and containing a metal material.