High-magnetic-field X-ray absorption spectroscopy of the heavy-fermion compound CeIrIn5 has been conducted to clarify the valence state of Ce at the metamagnetic transition. The field-induced change in the X-ray absorption spectrum near the Ce-L-3 edge is found to be smaller than the resolution limit of the measurement, suggesting that no field-induced valence change larger than 0.005 takes place at 2K up to 42 T.