This study investigated effects of school levels and years of teaching on the teacher's perceived competency of teaching English using an English subject-specific competency (ESSC) inventory of five constructs: language proficiency (LP), cultural teaching (CT), grammar translation teaching (GTT), communication skills teaching (CST), student-centred teaching (ST). 614 English teachers in Korea were surveyed. The results showed that English teacher perceived competency seems to be more related to school levels than years of teaching. The result of MANOVA showed the school levels and years of teaching have an effect on English teachers' competency. The results of ANOVA showed that three constructs (LP, CST, ST) were statistically significant with school levels, but only one construct, CST was statistically significant with years of teaching. Interaction effects showed that the means of LP and GTT increased by years of teaching for primary school teachers, but those for middle and high school teachers fluctuated slightly by years of teaching. These results suggest that the competence of English teachers should be understood in a multidimensional way with school level and experience variables. Pedagogical implications were discussed based on the findings.