Issues related to financial matters are an integral component of the curricula in vocational education and training in Switzerland. However, the differences between students' competences are caused not only by the curricula but by multiple factors. One key factor is teachers' characteristics that support successful learning processes. Teachers' conceptions with respect to general or domain-specific aspects of teaching-related phenomena and processes play a particularly important role. In contrast to subjects such as mathematics, little is known about teachers' conceptions in the domain of economics and financial literacy. This applies in particular to the investigation of the deep structure of teachers' conceptions, which goes beyond the designation of contents. A structural representation in the form of concept maps is a possible instrument for the collection and analysis of data to that end. Consequently, it is the aim of this study to demonstrate, how concept maps can be used as a methodological instrument in order to gain information about the domain-specific conceptions of vocational education and training teachers regarding the subject matter of financial literacy. Results show that concept maps are a targeted instrument for the exploration of the deep structure of conceptions and have therefore a great potential for research and teacher education.