This research aims to: 1. study the components of internal supervision; 2. develop an integrated supervision model to enhance teachers' competencies in active learning; 3. test the integrated supervision model to enhance teachers' competencies in active learning; and 4. evaluate the integrated supervision model to enhance teachers' competencies in active learning. The research methodology was divided into four steps: Step 1: Studying the components of internal supervision; Step 2: Developing a supervision model; Step 3: Pilot testing the internal supervision model; and Step 4: Evaluating the internal supervision model. The data providers consisted of 22 people, comprising 19 teachers and 3 educational supervisors. The research tools used included document synthesis, semi-structured interviews, and questionnaires. Statistical methods employed included the median, interquartile range, percentage, mean, and standard deviation.

              The research findings revealed that: 1. The study of internal supervision components consisted of 5 elements and 5 steps. 2. The development of an internal supervision model also consisted of 5 elements and 5 steps. 3. The overall effectiveness of the internal supervision model using the mentoring process was at the highest level. 4. The evaluation of the internal supervision model using the mentoring process concluded the following:  1) Overall, academic achievement in core subjects for students in grades 7 to 12 showed a improvement before and after the intervention. 2) Teachers' teaching competence was at a high level overall. 3) Satisfaction with the internal supervision model using the guided supervision process was at a high level overall.