Teachers' Innovative Behavior (TIB) is increasingly important for today's education. However, available instruments do not meet the complexity of TIB as an individual, collective, planned and unplanned construct. The aim of the present study was to construct a new instrument that meets the requirements of this complexity. We started with a compilation of the most suitable items from 12 existing questionnaires, selected by experts. After determining the most appropriate items, face-validity was investigated by interviewing primary and secondary school teachers concerning essential terminology. Lastly, with a sample of 178 primary and 159 secondary school teachers, we preliminary assessed the dimensionality of the questionnaire by means of an explorative factor analysis (EFA). The results show that the new questionnaire appears face-valid and structurally solid, but still needs to be tested in practice among large groups of teachers, in order to confirm dimensionality and other forms of validity.