A wiring board (1) includes: an insulator layer (21) composed mainly of ceramic; a conductor (3) extending through the insulator layer (21) in a thickness direction thereof; and an electrode pad (4) disposed on a first surface of the insulator layer (21) and connected electrically with the conductor (3), wherein: the electrode pad (4) includes through holes (4A) extending through the electrode pad (4) in a thickness direction thereof; and each of the through holes (4A) is positioned to avoid overlapping with the conductor (3) in the thickness direction of the insulator layer (21).

This configuration allows gas produced by vaporization of residue in a void (V) formed in a surface of the insulator layer (21), to be discharged via one of the through holes (4A) overlapping with the void (V). This serves to suppress the electrode pad (4) from undergoing a bulge through a heating process, and thereby improve the wiring board (1) in reliability of connection involving the electrode pad (4).

According to one aspect of the present disclosure, the electrode pad (4) further includes: a central part (41) in which the through holes (4A) are formed; and a peripheral part (42) surrounding the central part (41) without involving the through holes (4A).

This configuration serves to suppress the bulge from occurring in the central part (41) contributing to the connection between the electrode pad (4) and the conductor (3), and simultaneously improve the electrode pad (4) in strength of joint with the insulator layer (21) in the peripheral part (42).