A wiring substrate for electronic component inspection apparatus includes a first laminate which is formed by stacking a plurality of ceramic layers and which has a front surface and a back surface, and a plurality of studs joined to the back surface of the first laminate, wherein each of the studs is composed of a flange portion which is circular in bottom view, and a bolt portion which perpendicularly extends from a center portion of an outside surface of the flange portion; and in a vertical cross section along an axial direction of the bolt portion, the outside surface from which the bolt portion protrudes has a curved surface which is convex toward an inside surface of the flange portion facing the back surface of the first laminate.