The purpose of this study was to examine how various kinds of refreshments have effects on a concentration of brain activities determined by the NIRS. After the subjects performed mental-arithmetic for 10 minutes, they took a rest at a specified method and repeated mental-arithmetic for 5 minutes. We designated the three rest methods as follows:1. taking a deep breath,2. listening to a subject's favorite song, 3. listening to a classical music determined by examiners. In cases of taking deep breathing and listening to a classical music, there was the relaxation and subjects kept the concentration. Although the relaxation effect of the listening to a favorite song was the largest, the intensity of concentration was different by a subject, that is, the effect should be different by the music chosen by the subjects.