In order to prosper and survive in today’s continuously changing work environment, organizations need engaged employees, rather than merely “healthy” employees who are merely symptom free. However, the traditional approach of occupational mental health falls short because it focuses on preventing ill-health (e.g., burnout) rather than promoting health (e.g., work engagement). Accordingly, occupational mental health needs to use human resource management strategies to increase levels of employee engagement. The aim of this article is to consider really healthy worker and work place by focusing not only on negative but also on positive aspects of workers’ mental well-being. First, the concept of work engagement was introduced. Then, current situation of occupational mental health in Japan was mentioned. Finally, attention was paid to various strategies that can be used to improve employ mental well-being, whereby more collaboration between occupational health and management was emphasized.