This study is to develop a teacher’s happiness scale and to test its validity and reliability by examining factors and reasons of happiness experiences among teachers in Korea. We selected 100 teachers in Busan to conduct an open-ended question survey on how teachers perceive and experience happiness. Once a total of 59 questions were created as a result of the survey, they were administrated on 222 teachers for the factor analysis. Finally, 38 questions consisting of 10 factors were selected. A concurrent validity was tested by a correlation analysis with the satisfaction of the life scale and self-esteem scale completed by 198 teachers in Busan. The results showed that the correlation between the developed scale and the level of teachers’ happiness was high.