An information concealing label includes a label base and an adhesive layer on the back side thereof. The information concealing label is affixed by means of the adhesive layer onto an information writing section in which information to be concealed is written. The adhesive layer includes a strong adhesive portion positioned at the periphery of the label base and a weak adhesive portion positioned in the area inside the strong adhesive portion. The label base has a group of corrugated slits formed along the boundary between the weak adhesive portion and the strong adhesive portion. The weak adhesive portion of the label base can be peeled off the information writing section into an unsealed state with the strong adhesive portion adhering to the information writing section by cutting through the corrugated slits.