A substrate that enables increasing an allowable current value of a current path in a thickness direction of the substrate and narrowing spaces between multiple current paths, and the like are provided. To solve this subject, a substrate includes a sheet-shaped first base material (1) having a penetrating hole (1B) in the thickness direction and includes a second base material (2) fitted into the penetrating hole (1B). The second base material (2) includes multiple metal bodies (2B). The metal bodies (2B) penetrate in the thickness direction of the first base material (1) in a state of having an end exposed at each of a first surface and a second surface of the second base material (2) that face each other in the thickness direction.