School climate surveys are widely applied in school districts across the nation to collect information about teacher efficacy, principal leadership, school safety, students' activities, and so forth. They enable school administrators to understand and address many issues on campus when used in conjunction with other student and staff data. However, these days each district develops the questionnaire according to its own needs and rarely provides supporting evidence for the reliability of items in the scale, that is, whether an individual item contributes significant information to the questionnaire. The "Item Response Theory" (IRT) is a useful tool that helps examine how much information each item and the whole scale can provide. Our study applied IRT to examine individual items in a school climate survey and assessed the efficiency of the survey after the removal of items that contributed little to the scale. The purpose of this study is to show how IRT can be applied to empirically validate school climate surveys. (Contains 5 figures and 2 tables.)