The role of the educational supervisor in the central educational authorities is very important in promoting a administration and policy for national education. The purpose of this study was to develop a competency model that specifically presents the competency required for national educational supervisor as an exploratory study for the ministry of education. To this end, we analyzed the literature on the competency of educational supervisors in local educational authorities and national officials, and suggested the competency model of educational supervisor comprehensively by analyzing the content of interviews with experts and parties. The main research results are as follows. A competency model including 16 competency factors in 4 competency groups for educational researcher and 19 competency factors in 4 competency groups for educational senior researcher / senior supervisor was developed. The national educational supervisors should basically have competencies expected of a national official, and should also fully demonstrate the education competency. In addition, the higher the position, the more the competency factors to be equipped should be separated and deepened to suit the performance duties. The competency model developed in this research can be used as a diagnostic criterion for selecting and continuously strengthening the competency of educational supervisor, and it will be used effectively in developing the standard competency of education supervisor.