Vaporization of indium(III) mono- and polyphosphates was studied by high-temperature mass spectrometry. The molecules InPO₃ and InPO₂ were detected in the vapor for the first time. The standard heats of formation and atomization of these molecules at 298 K were calculated: -717±25 and 2021 ± 25 kJ mol^-1 for the former and -491±30 and 1546±30 kJ mol^-1 for the latter molecule, respectively.