[Subject] There is provided an otorhinolaryngological treatment device in which positioning of an expansion body inside a nasal cavity can be easily carried out without need for radioscopy.[Solution] A sinusitis treatment device includes: a flexible first elongated body 11 to be guided into an accessory an imaging unit 15 which is provided on the first elongated long body 11, for obtaining an image on the front side of a distal end of the first elongated body 11 a flexible second elongated body 12 having a lumen in which the first elongated body 11 is inserted an expansive body 13a which is provided on the second elongated body 12 and which has an effective expansive section 13a capable of radial expansive deformation within a natural ostium located between a nasal cavity and a paranasal sinus to push open a stenosed part of the natural ostium and a positioning unit M which is provided on the second elongated body 12 , for positioning the effective expansive section 13a of the second elongated long body 12 moved along the first elongated body 11 relative to the first elongated body 11.
