A directional coupling communication apparatus, comprising: a first module having a first coupler provided on a first insulating substrate, where an input/output connection line is connected to a first end of said first coupler and another input/output connection line is connected to a second end of said first coupler, wherein input signals may be input to both said input/output connection lines or output signals may be obtained from both said input/output connection lines; and a second module having a second coupler provided on a second insulating substrate, where an input/output connection line is connected to a first end of said second coupler, and another input/output connection line is connected to a second end of said second coupler, wherein input signals may be input to both said input/output connection lines or output signals may be obtained from both said input/output connection lines, wherein said first module and said second module are layered on top of each other so that said first coupler and said second coupler overlap at least partially as viewed in the direction in which said first module and said second module are layered on top of each other, signal coupling occurs using capacitive coupling and inductive coupling between said first coupler and said second coupler, the first coupler consists of a single coupler line, and the second coupler consists of a single coupler line, wherein when a first input signal is inputted at the first end of the first coupler and an inverse signal of said first input signal is inputted at the second end of the first coupler, a first output signal is outputted from the first end of the second coupler and an inverse signal of said first output signal is outputted from the second end of the second coupler, and when a second input signal is inputted at the first end of the second coupler and an inverse signal of said second input signal is inputted at the second end of the second coupler, a second output signal is outputted from the first end of the first coupler and an inverse signal of said second output signal is outputted from the second end of the first coupler. a first module having a first coupler provided on a first insulating substrate, where an input/output connection line is connected to a first end of said first coupler and another input/output connection line is connected to a second end of said first coupler, wherein input signals may be input to both said input/output connection lines or output signals may be obtained from both said input/output connection lines; and a second module having a second coupler provided on a second insulating substrate, where an input/output connection line is connected to a first end of said second coupler, and another input/output connection line is connected to a second end of said second coupler, wherein input signals may be input to both said input/output connection lines or output signals may be obtained from both said input/output connection lines, wherein said first module and said second module are layered on top of each other so that said first coupler and said second coupler overlap at least partially as viewed in the direction in which said first module and said second module are layered on top of each other, signal coupling occurs using capacitive coupling and inductive coupling between said first coupler and said second coupler, the first coupler consists of a single coupler line, and the second coupler consists of a single coupler line, wherein when a first input signal is inputted at the first end of the first coupler and an inverse signal of said first input signal is inputted at the second end of the first coupler, a first output signal is outputted from the first end of the second coupler and an inverse signal of said first output signal is outputted from the second end of the second coupler, and when a second input signal is inputted at the first end of the second coupler and an inverse signal of said second input signal is inputted at the second end of the second coupler, a second output signal is outputted from the first end of the first coupler and an inverse signal of said second output signal is outputted from the second end of the first coupler.