To provide a Fourier transformation device capable of highly precisely executing an arithmetic processing at high speed, reduced in the number of operation times and low in power consumption.

A since/cosine wave signal generation part 1 generates an analog DC signal and (2N-2)-pieces of analog sine/cosine wave signals sin(ωt), cos(ωt),... and outputs the signals. A Fourier coefficient transformation part 2 has respective variable resistance parts rr0, ri1, rr1, ri2,..., rr(N-1) and they change the resistance of the respective variable resistance parts in response to the change of the respective Fourier coefficient. An addition part 3 has an addition circuit 3-1 and resistance rf, and it adds outputs from the respective variable resistance parts, which correspond to the respective Fourier coefficients in the Fourier coefficient transformation part, and outputs the analog signals showing the added result.