While there are several scales that measure students' mathematical attitudes, few are focused on measuring students' attitudes towards geometry. Some of the scales present in literature measure different dimensions of students' attitudes towards geometry, such as their enjoyment of the subject, motivation to learn it, and perception of the usefulness of learning geometry. In the present study, we present an instrument that can be used to measure students' attitudes towards geometry by focusing on four factors: (1) students' enjoyment, (2) perception of the usefulness of learning geometry, (3) negative (or positive) factors underlying the learning of geometry, and (4) students' motivation to learn geometry. The instrument has been tested on a sample of 242 Italian high school students. An exploratory factor analysis has shown that the instrument is valid and the reliability of the instrument is high.