WIRING BOARD

PROBLEM TO BE SOLVED: To provide a wiring board which can inhibit decrease in wiring width to less than a predetermined wiring width while sufficiently ensuring electric connection reliability between a columnar electrode and wiring.SOLUTION: The present wiring board is a wiring board in which a plurality of insulation layers and a plurality of wiring layers are laminated. A columnar electrode is installed inside one of the insulation layers having one surface serving as a surface of the wiring board and another surface on the opposite side, and a pad provided on one end of the columnar electrode is exposed on the one surface. On the other surface, a recessed opening part with a bottom surface on which another end of the columnar electrode is exposed is provided, and wiring filling the opening part and connected with the other end of the columnar electrode via the opening is provided.