To provide a seal label for bags wherein it is simple to seal and unseal the bags such as document bag or an envelope and a commercially available plain bag can be used as it is.

The seal label 1 includes an easy-to-cut portion 3 where a bag can be easily unsealed by sticking while approximately being aligned with a tip of a cover piece of the bag, indications 4 and/or 5 of information necessary for communication, correspondence or the like applied on one or both of surfaces sectioned by the portion 3 and an adhesive applied on a rear face.