The school field practicum program is crucial for enhancing the teaching competencies of pre-service teachers. This study aimed to develop a suitable scale to evaluate how field practicum programs are operated in secondary schools and what outcomes pre-service teachers can achieve. To achieve this, the study reviewed previous research on secondary school field practicums and examined the field practicum programs in secondary school settings. Through expert consultations, 14 items for evaluating the operation process of secondary school field practicums and 9 items for evaluating outcomes were developed. Subsequently, the results from 130 student teachers from the College of Education at G-University, who responded to the school field practicum evaluation scale, were analyzed. To improve model stability and reduce measurement variables, an item parceling technique was applied to the evaluation scale. Exploratory and confirmatory factor analyses validated its factor structure, and reliability analyses assessed its internal consistency. The evaluation scale developed in this study can be used as a diagnostic tool for assessing the operational status and outcomes of secondary school field practicums and is expected to contribute to the development of the secondary teacher training system.