A robot cleaner includes a display unit, a camera unit configured to capture an image of a cleaning region when cleaning starts, a dust sensor configured to output a sensed signal corresponding to an amount of dust sucked in the cleaning region, and a control unit configured to calculate the amount of dust based on the sensed signal, to start an augmented reality (AR) mode when cleaning ends, to generate an AR image corresponding to the amount of dust, and to control the display module to superimpose the AR image on the image.