Although a lot of research and development has been conducted on the performance improvement of PEM (Proton Exchange Membrane) water electrolysis, the research on durability is still in early stage. This study investigated effect of temperature on the water electrolysis durability when driving temperature of the PEM water electrolysis was increased to improve performance. Voltage change, I-V, CV (Cyclic Voltammetry), LSV (Linear Sweep Voltammetry), Impedance, and FER (Fluoride Emission Rate) were measured while driving under a constant current condition in a temperature range of 50~80℃. As the operating temperature increased, the degradation rate increased. At 50~65℃, the degradation of the IrO2 electrocatalyst mainly affected the durability of the PEM water electrolysis cell. At 80℃, the polymer membrane and electrode degradation proceeded similarly, and the short resistance decreased to 1.0 kΩ·cm2 or less, and the performance decreased to about 1/3 of the initial stage after 144 hours of operation due to the shorting phenomenon.