Rates of oxygen absorption into water were studied in a rotating-disk gas-liquid contactor, in which liquid films were formed on the surface of disks rotating around the horizontal axis. When plain disks were used, values of the liquid-phase mass transfer coefficient k_L were lower than those predicted from the penetration model. However, with disks made of appropriate wire mesh, k_L, values agreed quite well with prediction by the penetration model for the range of gas-liquid contact time from 0.2 to 1.5 seconds.This type of gas-liquid contactor equipped with wire mesh disks seems to be a useful apparatus for studies of liquid-phase mass transfer in gas absorption.