The inductively coupled plasma etching of platinum withAr/Cl2gas chemistries is described. X-ray photoelectron spectroscopy (XPS) is used to investigate the chemical binding states of the etched surface with variousAr/(Ar+Cl2)mixing ratios. Atomic percentage of Cl element increases with increasingAr/(Ar+Cl2)mixing ratio with the exception ofAr/(Ar+Cl2)mixing ratio of 1. At the same time, the peaks that seem to be subchlorinated Pt at XPS narrow scan spectra are found and Cl–Pt bonds rapidly increase atAr/(Ar+Cl2)mixing ratio of 0.62. Quadrupole mass spectrometry (QMS) is used to examine the variations of plasma characteristics with variousAr/Cl2gas chemistries. QMS results show thatCl2molecules are converted to Cl radicals with adding Ar gas toCl2plasma. QMS results support the increased atomic percentages of Cl elements on the etched Pt surface. Single Langmuir probe measures ion current density with variousAr/Cl2gas plasma. Ion current densities are used to investigate the ion bombardment effects on the etched surface. Thin film thickness measuring system, scanning electron microscope and a four-point probe are used to extract the Pt etching characteristics. The maximum etch rate of Pt is approximately 140 nm/min at theAr/(Ar+Cl2)mixing ratio of 0.9. These results are consistent with XPS, QMS, and Langmuir probe data.