Magnetic and transport properties of cold rolled SUS304 stainless steels were investigated via measurements of X-ray diffraction, magnetization, thermoelectric power (TEP), thermal conductivity and electrical resistivity from 300 K down to low temperatures. Saturation magnetizations at 300 K were 1.6, 37.5, 72.6 and 105.6 emu/g for rolled thickness reduction ratios of 0, 33, 50 and 75%, respectively. The thermoelectric power (TEP) values at 300 K were found to be -1.3, -0.4, 1.6 and 2.9 V/K for the reduction ratios of 0, 33, 50 and 75%, respectively. Least-squares fits of the experimental data predicted a saturation magnetization of 141 emu/g and a thermoelectric power of 4.3 V/K for SUS304 in the martensite phase at 300 K.