The detection of human inner state such as “busyness” or “tiredness” have been conducted actively, thanks to the development of smartphones equipped with various sensors that are widely used. If people can recognize the factors contributing to human inner state, they will be able to regulate their own emotions and moods, by paying attention to them. I propose a system, “MyFactor,” that accumulates the sensor data of one’s smartphone and the annotation of his inner state, then extracts and provides the important factors contributing to it.