We constructed an analog circuit generating fluctuations of which a probabi
lity density function has power law tails. In the circuit, fluctuations wit
h an arbitrary exponent of the power law can be obtained by tuning the resi
stance. A theory of a differential equation with both multiplicative and ad
ditive noises which describes the circuit is introduced. The circuit is com
posed of a noise generator, an analog multiplier and an integration circuit
. Sequential outputs of the circuit are observed and their probability dens
ity function and autocorrelation coefficients are shown. It is found that c
orrelation time of the autocorrelation coefficient is dependent on the powe
r law exponent.