Cell performances of Cu(In,Ga)Se-2 (CIGS) thin-film solar cells were measured and analyzed as a function of temperature and illumination. The J(sc) and V-oc were linearly changed with the temperature in the range of 10 degrees C-70 degrees C. and the J(sc) was proportional to the illumination intensity in the range up to 130 mW/cm(2). It was shown that I-V curves in CIGS cells could be calibrated from the measured condition to other conditions such as the standard condition and field test ones, using the calibration method proposed for crystal Si solar cells.