Wiring substrate and semiconductor device

A wiring substrate of a coreless type, the wiring substrate comprising:

• a first insulating layer;
• a first wiring layer formed on the first insulating layer;
• an N number of insulating layers formed on a first surface of the first insulating layer and including a second insulating layer that covers the first wiring layer, wherein Nis a natural number greater than or equal to 1;
• a cavity formed in the N number of insulating layers and exposing a part of the first surface of the first insulating layer;
• an electronic component disposed in the cavity and including a first electrode covered by the first insulating layer;
• a filling insulating layer with which the cavity is filled covering the electronic component;
• first via wiring extending through the first insulating layer in a thickness direction and connected to the first electrode;
• and
• a second wiring layer formed on a second surface of the first insulating layer opposite the first surface and electrically connected by the first via wiring to the first electrode,
• wherein the cavity has an opening width that decreases toward the first insulating layer, and
• the first via wiring has a diameter that decreases toward the electronic component.