To provide a thermosensitive discoloring concealing material which performs secrecy-keeping of the contents of information, and can read the contents of the information with a convenient method without peeling the concealing material if required.

In the concealing material, a concealing layer, an erasing agent layer, and an adhesive layer which an electron-releasing dye colors on a support medium by an electron receptive developer are sequentially provided. In the thermosensitive discoloring concealing material, the concealing layer is erased at not less than higher temperature than at normal temperature.