The purpose of this study is to develop a scale for measuring state self-esteem using the Two-Item Self-Esteem scale (TISE) and to investigate its validity. State self-esteem, positive/negative experience of events and moods were rated once a day for 1 week in a Web-based surveys of adults. Concurrent validity was demonstrated by positive correlations between the TISE and pre-existing state self-esteem scale. Construct validity was established by correlations between the TISE and participants' both experience of events and perceived moods. The results indicate that state self-esteem increased in relationship to positive events and mood, and decreased in relationship to negative events and mood. The findings indicate that the state version of the TISE developed in this study is a valid tool for measuring state self-esteem.