ABSTRACT English for specific purposes is a process of teaching and learning English as a foreign language which is extended to learn English for certain circumstances. This study aims to find out the challenges of teacher’s in teaching English for specific purposes in vocational high school. A qualitative design with a case study was use to this research. Data were collected through face to face interview with the one and only English teacher at that school. In this study was selected sing total sampling. Thematic analysis was used to analyze the data. The result of the study reveal that three challenges for teacher in teaching English for specific purposes; students’ difficulties in learning English for specific purposes, teacher’s difficulties in teaching English for specific purposes and environmental support in teaching English for specific purposes. Keywords: English for specific purposes, computer and network engineering, teacher’s challenges.