PURPOSE: To eliminate a danger of a trouble such as a fall of a wafer by providing an intermediate coupling plate coupling a plurality of vertical bars to an intermediate part in the vertical direction so as to reduce distortion of the wafer due to a wafer load at the time of being subjected to high temperature treatment in a vertical type furnace.

CONSTITUTION: Four pieces of vertical bars 11a, 11a, 11b and 11b are coupled so as to fix their positional relations by an intermediate coupling plate 13 in the height direction of a wafer board 8a in the central part. According to the wafer board 8a for such a vertical type furnace, not only the vertical bars 11a, 11a, 11b, 11b are connected in both upper and lower ends by the coupling plates 12, 2 but also connected in the intermediate part by an intermediate coupling plate 13 so that distortion such as an overhang of an intermediate part of the vertical bars 11a, 11a can be checked by the intermediate coupling plate 13. Accordingly, distortion of a wafer due to load at the time of high- temperature treatment of a vertical type furnace can be reduced so as to eliminate a danger of a trouble such as fall of the wafer. Thereby, replacing frequency of the wafer board can be reduced.