We have produced porous 3C-SiC layers on silicon wafers by a carbonization method. By using this simple method, effects of impurities already doped in silicon wafers on the electrical properties of the SiC layers were characterized. The results showed that the sample formed from the high-doped wafer indicates higher conductivity values of the order of 10(5) similar to10(4) Omega(-1)m(-1) and also large Seebeck coefficients (similar or equal to +/-600 mu V/K) at a temperature range 400similar to500 degreesC. Therefore the porous 3C-SiC is expected to apply for thermoelectrical applications.