Ni-NiO1+x (0 ≤ x < 0.5) composites are prepared by hot isostatic pressing of a mixture of Ni and LiNiO2 or NiO powders (900°C, 2000 atm, 2 h). The samples are characterized by XRD and SEM. The composite material is used as the anode in the electrolysis of molten NH 4 F·2HF with and without LiF at 100°C and at 25 mA/cm 2 to produce NF 3 . The best current efficiency for NF 3 formation is ca. 53% on the Ni 5 mol% NiO composite anode. The composite anode is favorable for keeping a high current efficiency for NF3 formation and preventing the anode from corroding. -(TASAKA, A.; SUZUKI, Y.; OSHIDA, A.; MIMOTO, A.; HIEDA, T.; TACHIKAWA, T.; TAKAO, K.; TAKEMURA, H.; YAMAGUCHI, O.; J. Electrochem. Soc. 150 (2003) 6, D108-D116; Dep. Mol. Sci. Technol., Fac. Eng., Doshisha Univ., Tanabe, Kyoto 610-03, Japan; Eng.) -W. Pewestorf 37-011