The evaluation of human emotions has been a multi-disciplinary area of research interest. Human emotion that feel good or bad, like or dislike, interest or not interest in the case when we have been done the same routine, has some kind of relation in rhythm with the days or seasons. Although there are several methods for such evaluation, such as subjective evaluation and behavioral taxonomy, direct evaluation from the human brain is more reliable. Electroencephalograph (EEG) signal analysis is particularly widely used because of its simplicity and convenience. In the present study, human emotional states were investigated using a newly developed electroencephalograph device with a single electrode. The developed device is lighter and cheaper than existing devices, although its feasibility is yet to be proven. In our former study, we can confirm that the proposed simple device is robust for noise and effective for getting five emotions (concentration, stress, like, sleepiness, interest degree). In this study we could find the circadian rhythm about woman stress level using the pre-proposed method. This is said that there is some relation the hormone. We can obtain the hormone change using the emotion obtained by the EEG. Moreover, we can find the stress level change for sanitary goods.