Provided an endless belt-shaped electrophotographic belt comprising an electro-conductive base layer comprising a thermoplastic resin and carbon black, the base layer is a cylindrical extrusion product of a resin mixture comprising the thermoplastic resin and the carbon black, and when observing a cross section of the cylindrical extrusion product with a transmission electron microscope and obtaining an electron image under conditions of a resolution of 0.01 to 1 nm/pixel and a lowest gray of more than 0 and a highest gray of less than 255, and extracting from the TEM image a square region of 100 nm a side in which the carbon black occupies 50 area % or more, among pixels resulting from the carbon black and constituting 1% by frequency from the lowest gray in the square region, pixel group constituted by the pixels that are mutually adjacent, has an area of at least 10 nm2.