To unify temperature distribution in a wafer during rapid thermal processing, we calculated the effect of the heating control conditions on temperature distributions in the wafer during heat-up and at steady state by using a program for analyzing three-dimensional radiative heat transfer. We calculated optimum monitoring positions on the wafer in order to minimize the temperature distribution in the wafer. The effects of rotating the wafer, the spacing between the wafer and the shielding ring, the number of monitoring positions, and the initial non-uniform temperature distribution were also calculated. The minimum steady temperature distribution in the wafer at the optimum condition was calculated as ±0.1 K during 100 K/s heat-up and ±0.02 K at 1273 K steady state. We also developed a rapid parallel-computation technique to find the optimum heating control conditions for the whole heating process.