1. A multiple ROI (region of interest) setting apparatus comprising: an ROI setting unit which sets at least one or more ROIs and allocates ROI identification numbers to the each of ROIs by defining macro block as a pattern allocated to at least one ROI; a mapping unit which allocates at least one or more slice group identification numbers to the at least one or more ROI identification numbers; and a message generating unit which generates a message including ROI-associated information, slice-group-associated information, mapping information on mapping of the at least one or more ROI identification numbers to the at least one or more slice group identification numbers, and scalability information.