Provided are an artificial intelligence cleaning robot which establishes a cleaning plan in consideration of a previous cleaning history, and a method thereof. A method of operating a cleaning robot comprises dividing a cleaning area into a plurality of areas, storing a history of previous cleaning performed by the cleaning robot in a memory, establishing a cleaning plan based on the previous cleaning history stored in the memory and controlling the cleaning to be performed according to the established cleaning plan. Accordingly, it is possible to establish a cleaning plan with the reflection of a previous cleaning history, so that the cleaning efficiency of the cleaning robot can be improved.