The purpose of this study was to develop an instrument regarding teachers' belief, confidence and motivation of digital game-based learning pedagogies. A pool of 30 items was developed by revising items from Grove, Bourgonjon and Van Looy (2012)'s scale. A survey was used to examine and validate the instrument's structure and reliability. The participants include 134 in-service and pre-service teachers in Taiwan. An exploratory factor analysis with principal component method with varimax rotation was adopted to explore the factor structure of the instrument. Finally, a questionnaire was developed with a total of 13 items under three dimensions: confidence, belief and motivation. The internal reliabilities, alpha coefficients, were adequate for the overall scale (0.87) and for all the three subscales (0.83, 0.77 and 0.81, respectively). Applications of this instrument have been discussed at the end of this paper.