A method of collecting a nucleic acid from a sample containing a nucleic acid using a support of aluminum oxide having a surface where a water-soluble neutral polymer is adsorbed, the method including steps a to c: step a: a step of bringing the support into contact with the sample containing a nucleic acid to adsorb the nucleic acid on the support; step b: a step of bringing the support on which the nucleic acid is adsorbed into contact with a solution A containing 1 mM or more and 40 mM or less of a chelating agent; and step c: after the step b, a step of bringing the support on which the nucleic acid is adsorbed into contact with a solution B containing 50 mM or more of a chelating agent to elute the nucleic acid.