This paper presents the experimental results of the investigation of mechanical damage in Solid Oxide Fuel Cell (SOFC) under fuel starvation conditions using in-situ Acoustic Emission (AE) and electrochemical technique. The cell was oxidized electrochemically and AE signal has begun to be detected when the oxidation spread from anode/electrolyte interface to anode substrate after Ni/NiO equilibrium. The hydrogen was supplied again and AE signal detection was stopped. Before and after Redox cycling, OCV showed the same value, but the maximum power density decreased by 50 %. After experiment, there was delamination in anode/electrolyte interface, but there was not electrolyte cracking in active cell area. In this experiment, the decrease of maximum power density is thought to be due to causing delamination in anode/electrolyte caused by electrochemical oxidation.