Heat-sensitive recording medium

A thermally sensitive recording medium comprising a thermally sensitive recording layer containing a colorless or pale colored basic colorless dye and an organic color developing agent as main components on a support, wherein the thermally sensitive recording medium contains;

• a compound represented by the following general formula (1) as the organic color developing agent,
• wherein, Ra and Rb each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, A represents an integer of 1 to 6;
• B represents 0, 1, or 2, m1 and m2 each independently represent 0 or an integer of 1 to 3, but m1 and m2 are not both 0, Rc and Rd each independently represent a nitro group, a carboxyl group, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, m3 and m4 each independently represent 0 or an integer of 1 or 2, when m3 and m4 are both 2, Rc and Rd may be different from each other;
• M represents CO or NReCO, wherein, Re represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, when M is CO, m1 is 1, and when m1 is 0 and M is NReCO, B is not 0,
• and an oxalate compound represented by the following the general formula (2) as a sensitizer,
• wherein, R1 represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group.