Using the sessile drop technique, the contact angle between a liquid Fe–19%Cr–10%Ni drop and a dense alumina substrate was measured under H₂ as well as CO₂–H₂ atmospheres in the temperature range of 1753 to 1823 K. The measurements were carried out both in the static mode and the dynamic mode. The static measurements in hydrogen showed that the contact angle decreased from 135 to 107° by increasing temperature from 1753 to 1823 K. In the dynamic mode, gas mixtures of different oxygen partial pressures were imposed on the system. At 1753 K, the contact angle was decreased under the condition of oxide formation, whereas the contact angle was not changed under the condition of no oxide formation. At 1823 K, the contact angle did not change regardless of the oxide formation. The time required for the surface oxide layer to fully cover the liquid metal drop was decreased by increasing the temperature.