La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) -based honeycomb cell was first time successfully built and operated in the case of single-wall used condition and the full 4-walls cell one. Power generation characteristic of this honeycomb cell was measured from 700°C to 900°C by using various electrochemical techniques including polarization, current interruption and impedance spectrometry. The LSGM honeycomb cell shows the exact high power density compared with the ZrO2 based cell at the operating temperature range, and its value is 394 and 252 mW/cm2 at 800°C and 700°C, respectively. Thermal stability of this honeycomb cell is also studied and it is seen that the good performance through several times thermal cycling is observed. The 4-walls’s cell stack is successfully working at 800°C, and the volumetric power density is achieved to a value of about 700 mW/cm3.