A semiconductor sensor mount is formed as follows: through holes are formed that penetrate a glass plate; and then the glass plate having the through holes is dipped into hydrofluoric acid etchant to smooth the inner peripheral surfaces of the respective through holes. By etching the inner peripheral surfaces of the respective through holes after the through hole formation, minute roughness and cracks formed on the inner peripheral surfaces are removed, and thereby the areas for adsorbing gas are substantially reduced. That is, vacuums within the through holes can be maintained at a high degree during the anodic bonding, whereby undesirable electric discharge phenomena are prevented even if a relatively high voltage is applied during the anodic bonding. Accordingly, the yield of products can be improved while improving productivity.