When teachers organize planned and systematical out-of-school learning activities, students can understand the abstract and complex terms and topics better and therefore meaningful and deeper learning can occur. Within this context this study aims to develop a valid and reliable scale to determine the attitudes, behaviors, efficiency and competence of the teachers while teaching science on using the out-of-school learning environments supporting the in-class educational activities. The scale was administered to 520 teachers to evaluate the validity and reliability. An expert opinion was asked for the face and content validity of the scale and exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were made for the construct validity. The results of the EFA displayed that the scale includes 24 items under 4 different factors. After the EFA, CFA was made to verify the structures of the scale. The fit indexes obtained from CFA were acceptable. Therefore, it was inferred that the items of the scale were in accordance with the related models. Besides, the Cronbach's Alpha coefficient was calculated as 0.89. The analyses and obtained values revealed that the scale is valid and reliable.