The ampholytic surfactants show the nature of anionic surfactants in an alkaline region and the nature of cationic surfactants in an acidic region. As described below, the pretreatment solution of the present invention may preferably indicate alkalinity of pH 8.5 or higher, and therefore, it exhibits the nature of cationic surfactants by the use of ampholytic surfactants. As the ampholytic surfactants, those disclosed in JP 2011-228517 A can be used.