Crystal stand

Abstract

The wafer stage 10 includes: a ceramic plate 20 having a wafer mounting surface 21 on its upper surface and an electrode 22 therein; a conductive plate 30 disposed on the lower surface side of the ceramic plate 20; a bonding layer 40 bonding the ceramic plate 20 and the conductive plate 30; a ceramic plate through-hole 50 penetrating the ceramic plate 20; a dense plug 55 disposed in the ceramic plate through-hole 50 and allowing gas to pass through; and a gas introduction passage 60 disposed at least inside the bonding layer 40 and the conductive plate 30 and communicating with the ceramic plate through-hole 50. The bonding layer 40 has a structure in which a first insulating layer 41, a second insulating layer 42 and a first conductive layer 45 are laminated, the first conductive layer 45 being exposed in the bonding layer through-hole 64, the bonding layer through-hole 64 being the portion penetrating the bonding layer 40.