The book "Teacher Training for the Promotion of Process-Related Competencies" by Martin Reinold offers a comprehensive analysis of the success factors of teacher training programs. Through empirical studies, various design features are identified that are crucial for the implementation of the new mathematics curriculum in primary schools in North Rhine-Westphalia. The author conducts both quantitative and qualitative studies to illuminate the significance of subject-specific didactic stimuli for the acceptance and beliefs of teachers. Additionally, individual processes of belief development are elaborated, providing valuable insights into the effectiveness of the training programs and offering points for their optimization. This book is a valuable resource for anyone involved in the professionalization of teachers and the improvement of training offerings.