This is the operating manual of Mitsubishi Electric Air Conditioner, which includes safety precautions, part names, preparation before operation, automatic operation, manual operation, air flow velocity and direction adjustment, long operation, energy-saving cooling, timer operation, long-term non-use of air conditioner, maintenance, cleaning the catechin air filter, replacement of the air cleaning filter, contacting the service representative before checking again, troubleshooting, installation, relocation and inspection.