In order to realize a significant energy conservation and comfort of room air conditioners, we have developed a new structure indoor unit which drastically reviewed the internal structure for the first time in about half a century. This indoor unit improves energy saving performance by changing the shape of the air passage matching the air flow through the indoor unit from the upper side to the lower side, changing to the fan shape suitable for the air passage, and efficient arrangement of the heat exchanger. We reduced the power consumption of the indoor unit by 31% and improved the APF by 13.3% compared with the previous year. In addition, we realized an improvement in comfort by controlling the airflow making full use of the features of the new fan shape.