An optical system of an optical analysis device is easily evaluated with high accuracy.There is provided a method of evaluating an optical analysis device including an optical system A capable of forming a confocal volume C at a focal position by condensing excitation light B, the method including the steps of: placing, at the focal position of the optical system A, a phantom sample in which two or more types of solid members having different fluorescent substance concentrations are arranged adjacent to each other; irradiating the phantom sample 1 with excitation light through the optical system A while relatively moving the confocal volume C formed by the optical system A and the phantom sample in an arrangement direction of the solid members; detecting fluorescent light generated in the solid members placed in the confocal volume C; and evaluating the optical system A based on the detected fluorescent light.