This study used the Generalized Self-Efficacy Scale (GSE) to determine the staff's self-efficacy and examined its factor structure by using confirmatory factor analysis. A cluster random sampling and a simple random sampling design were used to gather the data from the sample of 46 fitness centers in Taiwan; 428 valid questionnaires were obtained. The researchers used mean, standard deviation, one-way ANOVA, skewness, kurtosis, and confirmatory factor analysis (CFA) to analyze and describe the GSE. The statistically significant findings show the GSE has good construct reliability and convergent validity; all model fit indexes are within the acceptable levels; there are positive relationships between the demographic variables and self-efficacy. The results of this study may attract the interest of upper-level managers to realize the circumstances of self-efficacy in fitness center staffs.