An experiment was performed to investigate the heat transfer characteristics of a latent heat storage unit with a circular-finned tube in melting and solidification processes. The experimental data were compared with thee values calculated by the numerical analysis shown in the 1st Report. In the solidification process, the experimental heat fluxes were 020 percent larger than the numerical calculations. It seems that this is due to the occurrence of dendrites. The influence of the Stefan number showing the heat capacity effect of a phase change material is small, as demonstrated by the numerical analysis. In the melting process, as the melting progresses, natural convection predominates over heat conduction. The heat fluxes obtained from the experiment are therefore much larger than the values predicted by the numerical analysis, taking account of the heat conduction only.