This paper examines how the introduction and utilization of new information technologies including AI, IoT and big data affect the well-being of workers including their mental health and job engagement, in addition to the types of workers and workplaces that are more influenced by the changes, based on worker panel data. First, looking at the situation of the introduction and utilization of new information technologies shows that workplaces that employ workers with more routine tasks, higher wages, longer working hours, and where there is a focus on operational efficiency, tend to introduce and utilize new information technology. Next, panel data estimation shows that well-being indices such as the mental health index and work engagement index tend to increase after the introduction and utilization of new information technology. Thus, the introduction and utilization of new technologies such as AI can be interpreted as improving well-being, including mental health and work engagement, meaning that the effect of supporting workers is greater than the negative effect caused by the extra workload or learning cost that workers must bear due to new technologies. In addition, it is shown that the impact of such new information technology on well-being is more evident for workers with clear job descriptions, high job discretion, frequent, suddenly changing work demands, and employed in workplaces that conduct work-style reform such as improving operational efficiency, reducing overtime work, promoting morning and evening non-work activities, and promoting paid holidays.