Provided is a semiconductor device that can suppress a leakage current more than has been achieved before. A semiconductor device 22 includes a first carrier holding layer 48, which is arranged on a lower electrode 47, is in contact with a lower electrode 47 via a first interface 49, and includes majority carriers of one type, and a second carrier holding layer 57, which is arranged on the first carrier holding layer 48, defines a second interface 58 constituting a conduction path to the first carrier holding layer 48, and includes majority carriers of the other type. The first interface 49 has its outline within the outline of the first carrier holding layer 48 when seen in a plan view in a direction that is orthogonal to a surface of the substrate, and the second interface 58 has its outline within the outline of the first carrier holding layer 48 when seen in the plan view.