The purpose of this study is to explore standards of elementary school teachers required for implementation of inclusive classroom. For the purpose of this study, in-depth interviews were conducted with 14 elementary school teachers who had experience of implementing an inclusive class for more than 3 years and received a reputation for running an inclusive class well from parents of students of disabilities, fellow teachers and pre-service teachers. Interview questions include attitudes toward implementation of inclusive classroom, classroom management strategies, and also instruction of students with disabilities in inclusive classroom. Findings of this study are as follows. First, teacher standards for implementing an inclusive classroom can be categorized into accountability, knowledge, and executive ability. Responsibility is formed based on the sense of homeroom for students with disabilities. Knowledge covers a wide range of contents necessary to implement an inclusive classroom such as disability, behavioral support for students with disabilities and classroom management strategies. And above all, the inclusive classroom can be successfully implemented only when various strategies are applied and practiced. Second, accountability, knowledge, and executive power are interdependent and only work meaningfully when all three factors are exercised. Third, the difficulty of operating an integrated class, which the participants in the study say, is the dual system of special education and general education and the school system that does not support integrated education, and the public system is used to cope with this. Implications were discussed based on the results of this study.