A directional coupler including a main line having an input terminal and an output terminal, and a sub-line having a coupling terminal and an isolation terminal, the main line, the sub-line, the input terminal, the output terminal, the coupling terminal and the isolation terminal being disposed within a laminate, wherein the main line and the sub-line extend in a loop shape in parallel with and spaced apart from each other by a gap such that electromagnetic coupling is generated therebetween and such that the main line is positioned outside the sub-line on a coupling layer, the input terminal, the output terminal, the coupling terminal and the isolation terminal are disposed outside the main line, and the main line is interposed between the output terminal and the sub-line.