A process for treatment of water containing an azole-type anticorrosive for copper, includes adding ferrous ions to the water containing the azole-type anticorrosive for copper and having a pH of 4-8, thereby precipitating an insoluble iron-azole complex, and separating the insoluble iron-azole complex. An amount of the ferrous ions added is 0.5 to 5.0 times, by molar ratio, an amount of the azole-type anticorrosive for copper in the water containing the azole-type anticorrosive for copper. After the insoluble iron-azole complex is separated, remaining total organic carbon (TOC) components are subjected to an ozone treatment.