A method to learn the second-order phase transition experimentally was demonstrated. The targeted phenomenon was the ferroelectric phase transition of triglycine sulfate, and simultaneous measurements of heat flow and pyroelectric current were performed while changing the temperature. Two fractions of the phase transition were calculated as a function of temperature for each of the measurement data, and quantitative analysis was performed. The analytical result of the experimental data was compared with the theoretical result of the Ising model. In addition to achieving a deeper understanding, the reduction in apparatus cost is considered.