The current understanding is that sleep associates profoundly with mental and physical health and life style-related diseases. Under the Ministry of Health, Labour and Welfare "The Sleep Guidelines for health promotion" was devised in 2003 and revised it in 2014. It is to promote that a citizen carries out a better sleep behavior in every life stage from infancy to old age. We comment on the 12 clauses of "The Sleep Guidelines" in this report. It shows the concrete methods for sleep well and the sleep disorder-related disease. We hope the 12 clauses will contribute to reducing a citizen troubled with daytime sleepiness. The night pleasant sleep is important in keeping mental and physical health.