PROBLEM TO BE SOLVED: To provide a thermosensitive recording material excellent in the storage stability (particularly plasticizer resistance) of images and the storage stability of the ground and a new diphenylsulfone derivative to be used therefor. SOLUTION: The diphenylsulfone derivative is represented by formula (III) (wherein each simbol has a respective predetermined meaning). The thermosensitive recording material comprises a thermosensitive recording layer containing a colorless or pale basic leuco dye and a color developing agent for color-developing the basic leuco dye, on a support, and at least one kind of the diphenylsulfone derivative represented by the above formula (III) as the color developing agent. COPYRIGHT: (C)2009,JPO&INPIT