In fact, teacher competency in the learning process is still low, teachers do not prepare learning tools before entering class, teachers have not been able to change the mindset of teaching towards learning that is based on active students or is still conventional. Teachers have an important role in an effective learning process so that learning objectives can be achieved so as to improve the quality of education which of course cannot be separated from the role of the school principal as a leader in realizing maximum performance with optimal results. The principal has one of the roles inherent in him, namely supervising the teacher's activities. Academic supervision is related to effective and quality learning. This research aims to see the comparison of supervised and unsupervised teachers in the classroom learning process by the school principal. The research uses a qualitative-descriptive approach with a case study method. Qualitative research aims to explain phenomena in depth and is carried out by collecting data and can be narrated well. Data collection techniques use interviews, observation and documentation studies. The research subjects were five state elementary schools in the Walisanga cluster, Bawang District, Banjarnegara, consisting of two schools as control schools because the principals were only acting principals and three schools carried out supervision. The research results show that teachers who are regularly supervised in the classroom learning process tend to have higher teaching effectiveness compared to teachers who are not supervised. Supervision has been shown to improve the quality of classroom management, use of varied learning methods, and student engagement, while unsupervised teachers are more susceptible to stagnation in professional development and face challenges in maintaining consistent instructional quality. The role of the school principal is very crucial in realizing the goals of quality education. The principal is the leader and person responsible for implementing quality learning in the school. One of the duties and roles of the school principal is to act as a supervisor and carry out supervision. Supervision carried out can provide an increase in teacher competence, whether pedagogical competence, personality competence, professional competence, or social competence, and the benefits of this are to provide an increase in self-confidence when teaching, provide educators with increased ability to manage learning, and build harmonious interactions. between teachers and school principals. The learning process in teaching plays an important role in the success of student learning.