A semiconductor device for a neural network and neural coupling of neurons which constitute the neural network comprising: a first semiconductor chip that includes a transmission circuit input unit, being a synaptic connection input unit, a transmission circuit unit connected to the transmission circuit input unit, and a transmission unit, having a transmission coil, connected to the transmission circuit unit; a second semiconductor chip that is disposed on or below the first semiconductor chip and includes a reception unit having a plurality of reception coils arranged as coaxial coils, wherein each of the reception coils is arranged independently and has a different area, a reception circuit unit connected to the reception unit, wherein the reception circuit unit has a reception coil selection unit configured to select any one of the plurality of reception coils, and a reception circuit output unit, being a synaptic connection output unit, connected to the reception circuit unit; a plurality of synaptic connection portions, each of which has a synaptic connection input unit and a synaptic connection output unit; and a plurality of neuron portions that are connected to each other via the plurality of synaptic connection portions; wherein the transmission unit and the reception unit are configured to communicate with each other in a non-contact manner, wherein the transmission circuit unit is configured to receive a transmission circuit unit input signal (Stx_in) having a predetermined transmission-side potential (Etx) via the transmission circuit input unit, the transmission circuit unit is configured to output a transmission circuit unit output signal (Stx_out) corresponding to the transmission circuit unit input signal (Stx_in), and the reception circuit unit is configured to receive the transmission circuit unit output signal (Stx_out) as a reception circuit input signal (Srx_in) via the non-contact communication between the transmission unit and the reception unit, the reception circuit unit is configured to output a reception circuit unit output signal (Srx_out) corresponding to a voltage of the reception circuit unit input signal (Srx_in) and having a predetermined reception-side potential (Erx), to the reception circuit output unit, characterized in that the reception coil selection unit is configured to change a weighting coefficient, w, of the synaptic connection portion by changing a ratio of the reception side potential, Erx, to the transmission-side potential, Etx, through the selection of the reception coil, and that the weighting coefficient (w) of the synaptic connection portion is reduced with time while the transmission circuit unit input signal (Stx_in) is not input to the transmission circuit input unit. a first semiconductor chip that includes a transmission circuit input unit, being a synaptic connection input unit, a transmission circuit unit connected to the transmission circuit input unit, and a transmission unit, having a transmission coil, connected to the transmission circuit unit; a second semiconductor chip that is disposed on or below the first semiconductor chip and includes a reception unit having a plurality of reception coils arranged as coaxial coils, wherein each of the reception coils is arranged independently and has a different area, a reception circuit unit connected to the reception unit, wherein the reception circuit unit has a reception coil selection unit configured to select any one of the plurality of reception coils, and a reception circuit output unit, being a synaptic connection output unit, connected to the reception circuit unit; a plurality of synaptic connection portions, each of which has a synaptic connection input unit and a synaptic connection output unit; and a plurality of neuron portions that are connected to each other via the plurality of synaptic connection portions; wherein the transmission unit and the reception unit are configured to communicate with each other in a non-contact manner, wherein the transmission circuit unit is configured to receive a transmission circuit unit input signal (Stx_in) having a predetermined transmission-side potential (Etx) via the transmission circuit input unit, the transmission circuit unit is configured to output a transmission circuit unit output signal (Stx_out) corresponding to the transmission circuit unit input signal (Stx_in), and the reception circuit unit is configured to receive the transmission circuit unit output signal (Stx_out) as a reception circuit input signal (Srx_in) via the non-contact communication between the transmission unit and the reception unit, the reception circuit unit is configured to output a reception circuit unit output signal (Srx_out) corresponding to a voltage of the reception circuit unit input signal (Srx_in) and having a predetermined reception-side potential (Erx), to the reception circuit output unit, characterized in that the reception coil selection unit is configured to change a weighting coefficient, w, of the synaptic connection portion by changing a ratio of the reception side potential, Erx, to the transmission-side potential, Etx, through the selection of the reception coil, and that the weighting coefficient (w) of the synaptic connection portion is reduced with time while the transmission circuit unit input signal (Stx_in) is not input to the transmission circuit input unit.