The present invention relates to a transmitting device and a receiving device. The transmitting device includes a controller, at least a feeding antenna and a plurality of transceiving modules. The controller generates a plurality of set of module control signals; the feeding antenna radiately transmits at least an internal transmission signal. Each transceiving module includes a plurality of transceiving units, and each transceiving unit includes a radiation slice and a transceiving circuit. A lengthwise edge of the radiation slice has a first end and a second end, and the first end and the second end of the lengthwise edge are toward an inner lateral side and an outer lateral side, respectively. The transceiving module performs transmission operation or reflection operation according to the module control signals.