Disclosed is a cervical collar, in which the cervical collar is configured such that the outer shell and the inner shell thereof are detachably separable. Thus, it is possible to remove an old inner shell in contact with the patients neck or jaw after use and attach a new inner shell, thereby repeatedly using the outer shell, so that sustainable utilization of resources is possible. In addition, since the cervical collar is adjustably used to have the height corresponding to the neck length of the patient by precisely measuring the neck length, it is possible to provide a correct fit and comfort can be improved when wearing the cervical collar. Further, since the Velcro is locked at a locked portion of an end of the outer shell in a three-point or four-point locking manner, it is possible to efficiently fasten the cervical collar.