Provided is a method applicable to the production of silicon wafers having crystal orientation or and consisting in specifying wafer-supporting positions on the occasion of heat treatment in a vertical heat treatment furnace as well as a heat treatment jig for use in carrying out that method. It becomes possible to suppress the shear stress which contributes to the extension of the slip generated at each wafer-supporting element contact point as an initiation, suppress slip growth and thus markedly improve the yield of heat-treated silicon wafers. The heat-treated wafer obtained by using the supporting method and the heat treatment jig has few slip, in particular has no long and large slip, and is high in quality.