Wiring board

A wiring board comprising:

• an insulating layer;
• a first pad and a second pad for external connection, provided on the insulating layer and including a first surface in contact with the insulating layer, a second surface opposite to the first surface, and a first side surface connecting the first surface and the second surface, respectively;
• and
• a protective insulating layer provided above the insulating layer, wherein:
• each of the first pad and the second pad has a portion exposed inside an opening in the protective insulating layer,
• the first pad has a portion opposing the second pad without the protective insulating layer interposed between the opposing portion of the first pad and the second pad,
• a region of the second surface of each of the first pad and the second pad exposed from the protective insulating layer is covered with a plating layer,
• a region of the first side surface of each of the first pad and the second pad exposed from the protective insulating layer is exposed from the plating layer, and
• an inner wall surface defining the opening in the protective insulating layer is separated from the insulating layer.