A security label 1 according to the present invention can be removably applied on an image photographing device such as a mobile phone 2 incorporating therein a digital camera to cover a lens part 3 thereof. Upon removal, the security label 1 is bent and makes a trace emerge which shows that the security label 1 has been removed. By applying the security label 1 to the mobile phone 2 to cover the lens part 3 thereof, improper photography can be prevented. In a case where the security label 1 is removed to take a photograph, the trace remains on the security label 1 even if the security label 1 is applied again on the mobile phone 2 to cover the lens part 3 thereof. Thus, the fact that a photograph is improperly taken can be easily understood.