After determining the size of oxygen precipitates and the residual oxygen concentration in a silicon wafer after heat treatment performed in a device fabrication process; the critical shear stress τcri at which slip dislocations are formed in the silicon wafer in the device fabrication process is determined based on the obtained size of the oxygen precipitates and residual oxygen concentration; and the obtained critical shear stress τcri and the thermal stress τ applied to the silicon wafer in the heat treatment of the device fabrication process are compared, thereby determining that slip dislocations are formed in the silicon wafer in the device fabrication process when the thermal stress τ is equal to or more than the critical shear stress τcri, or determining that slip dislocations are not formed in the silicon wafer in the device fabrication process when the thermal stress τ is less than the critical shear stress τcri.