Fluorine incorporated diamond-like carbon (F-DLC) films were deposited by RF magnetron sputtering method using a mixture of argon (Ar) and methane (CH 4) and tetrafluoromethane (CF 4) gases and a graphite target. The structure of the films changes from a diamond-like structure to polymer-like structure, with reduction of the hardness and Young's modulus of the films. The surface energy is decreased by the fluorine incorporation. The tribological test by a ball-on-disk friction tester in a deionized environment showed that 25 at.% F-DLC films exhibit the low friction. The antibacterial activity of the DLC films and the F-DLC films were also evaluated by bacterial eradication tests with Escherichia coli ( E. coli). The percentage eradication of E. coli attached to DLC films and 25 at.% F-DLC films was 40% and 56%, respectively. The antibacterial activity of the fluorine-free DLC films was improved by the fluorine incorporation.