Catalytic activity of a composite of Ni-Mn-Fe layered double hydroxide (LDH) and carbon gel (CG) for oxygen reduction reaction (ORR) was investigated. The effect of activation of CG on the ORR activity was also studied. The activation of CG and the combination of Ni-Mn-Fe LDH greatly enhanced the catalytic activity. Moreover, the catalytic activity and stability of the LDH-Activated CG (ACG) composite was confirmed as an air electrode.