An experimental lamp heated, rapid thermal processor (RTP) for an 8-in single silicon wafer was designed and established to investigate the thermal and flow characteristics in the processing chamber by transient temperature measurement and flow visualization. Experiments were carried out to explore the effects of placing a highly conducting copper plate right below the wafer on the uniformity of the wafer temperature and effects of the showerhead on the resulting flow distribution in the processing chamber. The measured data indicated that adding the copper plate can effectively reduce the nonuniformity of the wafer temperature. Besides, using a showerhead with finer holes in it results in a better flow distribution in the processor.