Both obesity (BMI over 30) and SAS are risks for Supper airway maintenance. We report an obese patient (BMI 33.5) with SAS who underwent awake craniotomy. Weight reduction was instructed 1 month before the operation, and the patient lost enough weight to use intraoperative MRI. Under general anesthesia, surgical pads containing 2% lidocaine with adrenaline were inserted into the nasal cavities. The patient's airway S was secured by i-gel® until dura was opened. A nasal airway was then inserted to confirm the upper airway patency and anesthetics were terminated The patient regained consciousness and started respiration. The i-gel® was removed. The nasal airway was changed to an RAE tracheal tube ; the tube was fixed above the vocal cords under bronchofiberscopic observation. Continuous positive airway pressure (CPAP) via RAE tube was started. Neither coughing nor epistaxis was observed.The RAE tube prevented glossoptosis and did not disturb speech mapping. Emergent endotracheal intubation was easily managed because the tube was close to the glottis. The RAE tube was removed and nasal CP AP was applied overnight Carefully prepared CP AP support via nasal RAE tube was practical in keeping upper airway patency for an obese patient complicated with SAS undergoing awake craniotomy.