Provided is a wiring board including: an insulating board having a mounting portion configured such that a semiconductor element is mounted on an upper surface thereof; a semiconductor element connection pad formed on the mounting portion; a conductor pillar formed on the semiconductor element connection pad; and a solder resist layer adhered on the insulating board. The solder resist layer has a first region with a thickness such that the semiconductor element connection pad and a lower end portion of the conductor pillar are embedded while an upper end portion of the conductor pillar protrudes, and a second region having a thickness larger than that of the first region and surrounding the first region.