Wiring substrate

A wiring substrate for mounting an electronic element, comprising:

• an insulating substrate comprising a corner constituted by two adjacent surfaces;
• and
• wiring located continuously across the corner, and wherein
• on at least one of the two adjacent surfaces, a part of the wiring disposed at an edge located at the corner has a thickness larger than a part of the wiring disposed away from the edge,
• one of the two adjacent surfaces is a main surface having an element mounting portion, and another of the two adjacent surfaces is a side-end surface,
• the thickness of the wiring on the main surface has a gradual increase from the part of the wiring disposed away from the edge toward the part of the wiring disposed at the edge,
• the thickness of the wiring on the side-end surface has a gradual increase from the part of the wiring disposed away from the edge toward the part of the wiring disposed at the edge, and
• a gradient of the gradual increase of the thickness of the wiring on the main surface is less than a gradient of the gradual increase of the thickness of the wiring on the side-end surface.