PROBLEM TO BE SOLVED: To provide a method for treating used sanitary articles reducing adverse effects on the environment and capable of efficiently performing the separation and recovery of a material such as fiber or SAP.SOLUTION: A method for treating used sanitary articles includes at least a process for macerating a sanitary article to disperse the same in water and a process for separating and recovering fiber and SAP and, in the process for macerating the sanitary article to disperse the same in water, a bleaching sterilizer and a crosslinking agent are added. Here, the crosslinking agent is added over many stages.