The professional teacher certification programme is a programme that has been implemented online for both in-service teachers and pre-service teachers since 2019. The change in the pattern of implementing the professional teacher programme from offline to online will provide a different programme experience for teachers, participants and tutors. The aim of this research is to measure the quality of service provided to the professional teacher certification programme participants using the SERVQUAL instrument. The instrument used was developed and analysed using confirmatory factor analysis (CFA). Subjects involved were 354 teacher respondents. Data analysis was carried out by SmartPLS version 3. The CFA results show that the model has met the fit index. Convergent and discriminant validity meet the criteria. The CR ranges between 0.948 and 0.989 and CA ranges between 0.917 and 0.985. Finally, the level of service quality provided to the professional teacher certification programme participants at Universitas Negeri Yogyakarta is in the very high level category.