In present psychiatric diagnosis, an interview by the psychiatrist is mainly adopted, which highly depends on knowledge and experience of the psychiatrist. Therefore, objective and quantitative psychiatric diagnosis is required. In this paper, non-invasive eye movement measurement apparatus for psychiatric diagnosis is investigated. The apparatus has an eye movement measurement function using image processing and target motion control function on monitor as a stimulus. Moreover, number of saccade occurrences is extracted from the measurement data of image processing by using the eye movement measurement system. The proposed system is applied both to healthy subjects and schizophrenic patients, and the results show the effectiveness of the proposed system.