A refractive index matching tape adhering device easily handles a refractive index matching film. The adhering device has a refractive index matching tape adhering portion which can be adhered by stretching the refractive index matching tape. In the adhering device having a refractive index matching tape supplying portion, a refractive index matching tape adhering portion, and a refractive index matching tape collecting portion, the refractive index matching tape adhering portion has a pair of tape supporting members which can stretch the refractive index matching tape and a cradle which holds the refractive index matching tape in the adhering.