A wiring board comprises an insulating substrate; and a heat-transfer member disposed inside the insulating substrate. The insulating substrate comprises an upper surface and a recess formed in the upper surface, the upper surface including a first mounting region for a first electronic component, and a second mounting region for a second electronic component which is provided in the recess. The heat-transfer member is disposed inside the insulating substrate so as to overlap the first mounting region and the second mounting region as seen in a plan view, and, part of the heat-transfer member is exposed in the recess.