PURPOSE: To improve optical character reading aptitude in a specified wavelength area by adding at least one kind of fluoran derivative to be expressed by a specified formula as a basic dye and at least one kind of spiropyrane derivative in a recording layer of a thermal recording body.

CONSTITUTION: In a thermal recording body having an excellent optical character reading (OCR) aptitude in a wavelength area of 650-700nm and having a recording layer which contains a colorless or light color basic dye and a coloring agent formed on a support body, the recording layer contains at least one kind of fluoran derivative to be expressed by a formula I as a basic dye and at least one kind of spiropyrane derivative to be expressed by a formula II. In the formulas, R1, R2 represent 1-6C alkyl group, R3 R4 represent hydrogen atom or 1-4C alkyl group, and R5, R6 represent 1-6C alkyl group or benzil group.