The present invention allows an organic EL display device to perform display with high definition by reducing an area of each pixel forming a display region of the display device. A drive TFT for driving an organic EL element, a storage capacitance connected with a gate of the drive TFT, and a switching TFT connected to a scanning line are used in common by pixels arranged adjacent to each other in the lateral direction and hence, areas occupied by these circuit elements per one pixel can be reduced whereby the pixel can be made small. Further, a data line for supplying a video signal and a power source line for supplying an electric current to the organic EL elements can be used in common by the pixels arranged adjacent to each other and hence, the number of data lines and the number of power source lines can be halved thus reducing an area of the pixel. Due to such a constitution, the present invention acquires an organic EL display device capable of performing display with high definition.