A substrate structure includes a first portion, a second portion, and an intermedia portion disposed between the first and the second portion and the electrically connected business. The first portion includes a first fine redistribution layer (RDL) and a first coarse RDL. The first coarse RDL includes a first coarse conductive pattern, electrically connected to the first fine conductive pattern, where a, the first coarse RDL includes a first coarse conductive pattern Layout density of the first fine conductive pattern is denser than that of the first coarse conductive pattern. The second portion includes at least one of a second fine RDL and a second coarse RDL. An electronic device including a substrate structure is also provided.