The determination of In(III) in indium tin oxide (ITO) targets sample by flame atomic absorption spectrometry is reported. The relevant sample was at first decomposed by means of aqua regia digestion technique and then analysed. The conventional air-acetylene flame was used for direct analysis. It was not required to use matrix-matched standard or technique of standard additions in the process of calibration and measurement. The Beer’s law obeyed the concentration range up to 10 mg L−1. Limit of detection (3σ criterion) reached the value of 0.4 mg L−1. Sensitivity of determination expressed as characteristic concentration was equal to 0.36 mg L−1. Repeatability of analysis (n = 5) did not exceed ±1% for analytical determination of sample in question. The method was successfully applied to In(III) leachable content measurement in the ITO targets sample and the result is in very good agreement with this independently obtained by reference method – inductively coupled plasma with atomic emission spectrometry.