The aim of this study was to create an instrument to measure elementary teachers' interest in teaching chemistry. The interest in chemistry teaching instrument (ICTI) was created to measure both the affective and cognitive components of interest. After establishing the face and content validity of the instrument, the internal consistency of the instrument was verified by calculating Cronbach's alpha for the items. This was done using questionnaire data collected from 149 Finnish elementary teachers teaching chemistry in integrated chemistry and physics lessons. Exploratory factor analysis (EFA) was used to identify the underlying dimensions of interest. Based on the results of the factor analysis, elementary teachers' interest in chemistry teaching had two components: personal and value-related. The usefulness of the ICTI instrument was tested by conducting a correlation analysis of the measured level of interest and the reported use of teaching methods. As expected, the results indicated a positive correlation between the elementary teachers' interest measured with ICTI and the use of for example inquiry-related methods: creative problem solving and laboratory work. The ICTI may be used, for example, to evaluate and develop in-service and pre-service teacher training.