This study has been carried out to develop a tool to measure the level of anxiety of students studying in the 10th and 11th grades of high schools in Turkey. The scale has been created by the application of a pool of items consisting of 45 sentences based on student opinions and expert advice to 365 students and the branching of the results with the "Classification Trees" method to prepare a tree of 23 leaves. The prepared scale is called the Anxiety Tree and is a suggested guidance tool to identify existing anxieties about chemistry for chemistry teachers. It has features to be used as a tool to measure performance. (Contains 3 tables and 1 figure.)