A new experimental method to detect critical temperatures in solids basing on the single measurement of the chemical potential temperature dependence is proposed. To demonstrate the applicability of the method we perform a simple electrochemical experiment on three metallic samples: Gd 5 Si 4 , TiNi and CuAlNiTiMn alloys. The indirect measurement of the chemical potential as function of temperature for these materials localizes the critical temperatures connected with different types of phase transitions, here either magnetic (Gd 5 Si 4 ) or structural (TiNi, CuAlNiTiMn) ones. The values of the critical temperatures obtained in this way stay in good agreement with the existing literature data and confirm general theoretical predictions. The details of the obtained plots point out also the beginning and the end of each transformation.