The purpose of this study is to develop a reliable and safe scale for determining the self-efficacy levels of science teachers in the teaching of astronomy subjects. The study used a survey approach, which is a qualitative research method. The study was conducted with a total of 106 science teachers working in the secondary schools of Ordu city centre and the surrounding towns during the academic year 2016-2017. While forming the item pool of the scale, scale development studies within the

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... xt of teacher self-efficacy and the special field competencies of science and technology teachers determined by MOE (2008) was used. In addition, the compositions written by eight science teachers outside the study group about the teaching of astronomy were also used for item pool. For the content validity of the scale, an expert opinion form was prepared to assess the content validity rate and kappa coefficient of agreement, and this was presented to six faculty members in the science teaching department. The construct validity of the scale was investigated via exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The results of EFA showed that the scale construct included a total of three factors and 13 questions, and explained 70.60% of the total variance. CFA results showed that the chi-squared value and the degrees-of-freedom rates (c2/sd = 1.67) were perfect, and the other fit indices showed a good fit (GFI = 0.86, CFI = 0.94, NNFI = 0.92, IFI = 0.94, SRMR = 0.08 and RMSEA = 0.06). The results of the reliability analysis showed that the Cronbach's alpha reliability coefficient was 0.84 for the whole scale, 0.90 for "student outcomes through astronomy teaching" factor, and 0.83 for both "astronomy teaching strategies" factor and "difficulty in astronomy teaching" factor. In conclusion, the results obtained showed that "Astronomy Teaching Self-Efficacy Belief Scale" can be used as a valid and reliable assessment instrument.