Plasma characteristics, excitation temperatures of atomic iron and electron densities, were compared between the laser-induced plasmas generated on solid steel at room temperature and molten steel. The excitation temperatures of iron atom were determined by Boltzmann plot using neutral iron atomic emission lines in the wavelength range of 386 to 400 nm. Electron densities were estimated by measured linewidths of AlⅠ394.4 nm. Excitation temperature of iron decreased from 10 800 K at 10 μs to 7 300 K at 80 μs of delays for solid steel. Excitation temperatures were not distinguishable between the plasmas generated on solid and molten steels at delays of 10 and 70 μs, respectively. The linewidths observed with molten steel were narrower than those observed with solid steel in most of neutral atomic lines of iron and aluminum. Electron density in the plasma produced on molten steel was estimated to be (0.99±0.15)×10¹⁷ cm^-3, which was 46% of electron density in the plasma on solid steel at the same observation delay of 10 μs from the laser pulse.