A new in-service teaching certificate system, the TEE Certificate system, was launched for Korean teachers of English with the aim of encouraging them to use English in their daily teaching practice. This study attempts to investigate key issues regarding the current development of the TEE Certificate system and addresses the implications for a successful TEE policy in Korea. It employs document analysis produced by the Ministry of Education, Science and Teclmology and to key Regional Offices of Education and semi-structured interviews with 15 supervisors, 11 teachers and 2 TEE Certificate examiners. The research findings suggest that there is a gap regarding the aims of the TEE Certificate system among stakeholders, leading to the different attitudes toward it. Those who have positive perceptions of the system see it as a tool for encouraging Korean teachers of English to develop their English language teaching competence. On the other hand, those who have negative attitudes see the negative aspects such as another type of burden on teachers and even the possibility of a form of lay-off. The new strategies of how to use the system are required to make it play a proper role in terms of the provision of an English-fi'iendly learning environment and supporting teachers' professional development.