A 61-year-old man, who suffered from Charcot-Marie-Tooth disease (CMT) for 44 years, was evaluated for the respiratory disorder. He had diaphragmatic dysfunction induced by phrenic nerve disturbance. In this patient, central type apnea and hypopnea related to diaphragmatic weakness occurred during REM sleep, which induced accessory inspiratory muscle inhibition. Respiratory muscle dysfunction had not been generally recognized in CMT until recently, but its significance should be emphasized.