This study aimed to develop an instrument-principals’ trust in elementary school teachers scale. Based on the literature review of instruments developed to measure trust and how principals perceive teachers’ behaviors and attitudes to form the trust between them, a conceptual model and initial items were developed. Next, through expert judges and pilot tests, 50 items were developed. A total of 241 principals from elementary schools provided usable data as measured by the principals’ trust in teachers scale. Item data were analyzed by exploratory factor analysis and confirmatory factor analysis. As the result, it was shown that the conception of elementary school principals’ trust in teachers consists of 5 factors, that is ‘Collaborative relationship with fellow teachers’, ‘Understanding and caring for students’, ‘Support and respect in the principal’, ‘Partnership with parents’, ‘Teacher s trust in principal perceived by the principal’. It turns out that elementary school principals value the characteristics and attitudes of teachers in various relationships surrounding teachers. It suggested that in order to develop a warm educational community in a culture of trust formed between teachers and elementary school principals, it is necessary to reflect programs that competencies and attitudes necessary to trust each other to improve them in the principal training and teacher training.