PURPOSE: To reduce an inside diameter error at piercing by a laser, by piercing separately a through-hole on plural plate bodies by laser light, and subsequently, sticking the plate bodies so that each through-hole communicates on the almost same axis.

CONSTITUTION: Plural plate bodies 1 in equal thickness are made by a ceramics material of silicon nitride, etc. A through-hole 3 is pierced separately on the same part of each plate body 1 by laser light 2. Subsequently, the plate bodies 1, 1 are stuck by an adhesive agent with a large diameter side of the through- hole 3 faced outside. In such a case, they are stuck so that the through-hole 3 communicates on the almost same axis. Wire lapping work is applied to a through-hole 4 formed by making each through-hole 3 communicate, and an abrasive finishing is executed so that said hole has a uniform inside diameter. According to such a method, an inside diameter error or the irradiating side and the opposite side, which follows piercing work by laser is reduced.