Disclosed is an instrument for treating a patient with semicircular canal injury, which is an instrument in the form of an exact enlarged model of human three semicircular canals having a structure wherein a liquid and a plurality of otolithic models, having a specific gravity larger than the specific gravity of said liquid, are enclosed within a hollow annular member made of a transparent resin and equipped with a screen at the position corresponding to the cupula in each of the three semicircular canals. Therein, said screen has such a mesh size as allowing the passage of said liquid but not allowing the passage of the otolithic models. Thus, an instrument for treating a patient with semicircular canal injury, whereby physical and mental pains can be alleviated in treating a patient with semicircular canal injury such as benign paroxysmal positional vertigo, is provided.