Provided is a wiring substrate which maintains low connection resistance and high thermal conductivity even in the case where the substrate operates repeatedly and which has high endurance. A wiring substrate (10) comprises a substrate (11) having a plurality of through-holes (3), a through-hole conductor (4) formed on the inner wall of the through-hole (3), a wiring (2) formed on at least one surface of the substrate (11) and electrically connected with the through-hole conductor(4), and a metal post (5) one end (5a) of which is inserted in an inner space surrounded by the through-hole conductor (4) to be in contact with and electrically connected with the through-hole conductor (4) and the other end (5b) of which is formed of a column-shaped conductor protruding from the surface of the substrate. In the wiring substrate (10), the other ends (5b) protruding from the surface of the substrate (11) of the plurality of metal posts (5) can be positioned on the same plane.