A display device and a method for replacing an advertisement are provided. The display device includes a display, a first communication circuit which receives first content from a broadcast receiving device, a second communication circuit which receives second content from an external server, and a processor electrically connected with the first communication circuit and the second communication circuit. The processor is configured to determine whether a first volume image applied by the broadcast receiving device is present in the first content, while outputting the second content, and overlay the first volume image or an alternative volume image corresponding to the first volume image with the second content to display an overlaid result on the display, if the first volume image is contained in the first content.