This research aims to develop an independent scale that measures the critical thinking attitudes of classroom teacher candidates. The research was designed in a screening model. The universe of the research was composed of 384 prospective teachers who are studying in the education faculty of a university in the western part of Turkey. In the sample of the research was composed; classroom teacher and preschool teacher departments. Explanatory and confirmatory factor analysis was performed on the obtained data. The validity of the construct obtained by confirmatory factor analysis with the data was tested. According to research findings, "Critical Thinking Attitude Scale (CTAS)" is a valid and reliable measurement tool consisting of 19 items and 5 sub-dimensions (Information Acquisition Willingness, Reasoning, Discovery, Evidence-Based Decision Making, Self-Regulation). The maximum score that can be obtained from the scale is 95 and the minimum score is 19. The scale is suitable for use in the 17-25 age groups.