An anticorrosion test method for a coated metallic material in which a surface-treated film is provided to a metallic base material (2, 3), the anticorrosion test method for the coated metallic material comprising: a preparation step of adding an artificial flaw that penetrates the surface-treated film and reaches the metallic base material (2, 3) at two mutually-separated positions in the coated metallic material; a first measurement step of measuring a size of the artificial flaw; a connection step of electrically connecting the artificial flaws at the two positions by an external circuit via water-containing materials, each of which is in contact with a respective one of the artificial flaws; an energization step of energizing the metallic base material (2, 3) by the external circuit so as to produce a bulge of the surface-treated film in at least one of the artificial flaws at the two positions; a second measurement step of measuring a size of the bulge of the surface-treated film; a calculation step of calculating a degree of progress of corrosion of the coated metallic material in relation to one of the artificial flaws at the two positions having the larger bulge of the surface-treated film on the basis of the size of the artificial flaw, which is measured in the first measuring step, and the size of the bulge of the surface-treated film, which is measured in the second measurement step; and a correction step of correcting the degree of the progress of the corrosion of the coated metallic material, which is calculated in the calculation step, on the basis of the size of the artificial flaw having the larger bulge of the surface-treated film and correlation, which is calculated in advance, between the size of the artificial flaw and the degree of the progress of the corrosion of the coated metallic material, wherein the correlation is a correction coefficient that corresponds to or is defined according to the size of the artificial flaw. a preparation step of adding an artificial flaw that penetrates the surface-treated film and reaches the metallic base material (2, 3) at two mutually-separated positions in the coated metallic material; a first measurement step of measuring a size of the artificial flaw; a connection step of electrically connecting the artificial flaws at the two positions by an external circuit via water-containing materials, each of which is in contact with a respective one of the artificial flaws; an energization step of energizing the metallic base material (2, 3) by the external circuit so as to produce a bulge of the surface-treated film in at least one of the artificial flaws at the two positions; a second measurement step of measuring a size of the bulge of the surface-treated film; a calculation step of calculating a degree of progress of corrosion of the coated metallic material in relation to one of the artificial flaws at the two positions having the larger bulge of the surface-treated film on the basis of the size of the artificial flaw, which is measured in the first measuring step, and the size of the bulge of the surface-treated film, which is measured in the second measurement step; and a correction step of correcting the degree of the progress of the corrosion of the coated metallic material, which is calculated in the calculation step, on the basis of the size of the artificial flaw having the larger bulge of the surface-treated film and correlation, which is calculated in advance, between the size of the artificial flaw and the degree of the progress of the corrosion of the coated metallic material, wherein the correlation is a correction coefficient that corresponds to or is defined according to the size of the artificial flaw.