A network approach has been used to analyze; the conditions of linearity of the current-time relationship in electrochemical systems. A network model for a simple electrodiffusion process in an electrochemical cell with blocking electrodes has been proposed. With this model and the electric circuit simulation program PSPICE, a decomposition into Fourier components of the current-time response, which follows the application of a sinusoidal-shaped potential difference between the electrodes, is obtained. This spectral analysis allows for the precise determination of the parameters of the input perturbation for which the conditions of linearity of the system are obeyed.