A mechanical nasal dilator includes a frame provided with support plates (6,6') at its ends, the frame including a central extranasal portion (1) and two intranasal portions (2,2'), wherein the extranasal portion (2) of the frame is globally U-shaped, whereof the central portion is elastic and spaces apart the nose wings by spring effect, the end of each of the branches of the U being itself U-shaped whereof one branch forms one part of the extranasal portion of the frame and the other branch, located between the branches of the extranasal portion of the frame, forms the intranasal portions (2,2').