Provided is a lithium air battery, and more particular, a lithium air battery including a buffer layer consisting of a conductive ion-exchange resin and a mesoporous carbon formed between an electrolyte and a catalyst layer configuring a cathode to prevent a contact between the catalyst layer and a large amount of electrolyte in the lithium air battery, thereby reducing occurrence of overvoltage at the time of charging and discharging the battery. At the same time, the lithium air battery of the present invention may suppress evaporation of the electrolyte solution to improve durability, thereby preventing deterioration in performance of the battery, and extending a lifespan.