Tolerance, subjective and objective effectiveness of domestic intraoral applicator UPLH-01 were studied in the treatment of snoring and obstructive sleep apnea (OSA). In 44 patients with uncomplicated snoring the above parameters were assessed using questionnaire, in 20 patients with uncomplicated snoring and OSA paired polysomnographic investigations were made. Tolerance of the treatment was 50%. Subjective positive effect was registered in 65% of the patients. The applicator was found effective in the majority of patients with uncomplicated snoring. In mild and moderate OSA the applicator was effective only in a few cases. In severe OSA no effect was found. Patients with chronic disorders of nasal breathing exhibited deterioration of respiration and blood saturation with oxygen. Thus nasal obstruction is a contraindication to applicator use.