A corrosion resistance test method for a coated metal material that includes a metal base (2, 3) and a surface treatment film provided on the metal base (2, 3), the corrosion resistance test method comprising the steps of: disposing one or more water-containing material holders each holding a water-containing material to be in contact with the surface treatment film and one or more electrodes to be in contact with the water-containing material contained in the one water-containing material holder or in each of the water-containing material holders, and electrically connecting, with an external circuit, between the one electrode and the metal base (2, 3), or between the electrodes; and supplying a current between the one electrode and the metal base (2, 3), or between at least one of the electrodes and at least one of the other electrodes, as an anode and a cathode, respectively from a current supplier provided on the external circuit to bring corrosion of the coated metal material to progress, wherein the water-containing material comprises water, an electrolyte material, and kaolinite, the electrolyte material being a mixture of NaCl, Na 2 SO 4 and CaCl 2 each having mass % of between 1.9 and 2.1, respectively, and the content of the kaolinite in the water-containing material is 38.8 mass% or more to 41.0 mass% or less, preferably 40.1 mass% or more to 41.0 mass% or less, and wherein the heat retaining property of the water-containing material examined by the following method is less than 0.5°C: 8 mL and 1.1 mL of the water-containing material are introduced into respective water-containing material holders, then, the temperature of the hot plate disposed on the metal base (2, 3) of the coated metal material is set to 61 °C and kept for 30 minutes, thereafter, the temperature of the water-containing material within 5 mm from the interface between the surface treatment film and the water-containing material is measured, and the heat retaining property of the water-containing material is evaluated using the temperature difference between the 8 mL case where the amount of the water-containing material introduced is 8 mL and the 1.1 mL case where it is 1.1 mL. disposing one or more water-containing material holders each holding a water-containing material to be in contact with the surface treatment film and one or more electrodes to be in contact with the water-containing material contained in the one water-containing material holder or in each of the water-containing material holders, and electrically connecting, with an external circuit, between the one electrode and the metal base (2, 3), or between the electrodes; and supplying a current between the one electrode and the metal base (2, 3), or between at least one of the electrodes and at least one of the other electrodes, as an anode and a cathode, respectively from a current supplier provided on the external circuit to bring corrosion of the coated metal material to progress, wherein the water-containing material comprises water, an electrolyte material, and kaolinite, the electrolyte material being a mixture of NaCl, Na 2 SO 4 and CaCl 2 each having mass % of between 1.9 and 2.1, respectively, and the content of the kaolinite in the water-containing material is 38.8 mass% or more to 41.0 mass% or less, preferably 40.1 mass% or more to 41.0 mass% or less, and wherein the heat retaining property of the water-containing material examined by the following method is less than 0.5°C: 8 mL and 1.1 mL of the water-containing material are introduced into respective water-containing material holders, then, the temperature of the hot plate disposed on the metal base (2, 3) of the coated metal material is set to 61 °C and kept for 30 minutes, thereafter, the temperature of the water-containing material within 5 mm from the interface between the surface treatment film and the water-containing material is measured, and the heat retaining property of the water-containing material is evaluated using the temperature difference between the 8 mL case where the amount of the water-containing material introduced is 8 mL and the 1.1 mL case where it is 1.1 mL. 8 mL and 1.1 mL of the water-containing material are introduced into respective water-containing material holders, then, the temperature of the hot plate disposed on the metal base (2, 3) of the coated metal material is set to 61 °C and kept for 30 minutes, thereafter, the temperature of the water-containing material within 5 mm from the interface between the surface treatment film and the water-containing material is measured, and the heat retaining property of the water-containing material is evaluated using the temperature difference between the 8 mL case where the amount of the water-containing material introduced is 8 mL and the 1.1 mL case where it is 1.1 mL.