Interest is not only regarded as a prerequisite for learning motivation but also an educational objective. There is however a major concern regarding the frequently observed decline during students' school careers [1]. Therefore, in general education and particularly in physics education great importance is attached to fostering students' interest and a lot of research has been conducted in this regard. To measure students' interest, a number of well-established research scales are available for German-speaking countries, which are primarily based on two constructs of interest. One common construct by Hoffmann, Häußler and Lehrke differentiates between the interest that students show in physical contents and their interest in physics as a school subject [2, 3]. In addition, another construct by Krapp widely used in educational psychology distinguishes between the emotional- and value-related significance of an activity or its content [4]. So far, these two constructs have largely been used unrelated. For the study presented in this paper, they have been connected resulting in four different combinations of emotional and value-related significance attributed to physical contents and physics lessons. These constitute four possible scales which have been integrated in a questionnaire and evaluated in a sample of N = 1529 high school students. An exploratory as well as a confirmatory factor analysis has been performed to test the assumed theoretical structure of the underlying constructs. Our data suggests that a revision of the combined scales is necessary as two of the four coincide: all items including emotional valences load on one factor only, while items with value-related valences are distinguishable between interest in physical contents (factor two) and interest in physics lessons (factor three). In this paper we present our study supporting this newly developed measurement model and according research scales for high school students' interest in physics.