[en] Recently, a new method for electrochemical etcing of fission and alpha-tracks in thin aluminized plastic detectors was proposed by Tommasino et al. By using the new ECE-method, the electirc-tree-induced perforations through nuclear tracks in plastic foils are non-shorting with aluminium at positive polarity, due to an insulating anodic oxid formation. Therefore, a fast dissolution of the aluminium layer by basic electrolyte can be avoided. Authors have studied the main trends of the growth of mean diameter of spots dissolved around fission tracks in aluminized PET foils as a function of the strength of electric field, frequency of voltage and time of etching in 30% KOH, with using both DC and AC voltages and without using field. it is proved that the electric field greatly enhances the rate of etching along the tracks. With irradiation under vacuum a considerable delay in spot appearance is observed. This effect can be partially reduced by using a regeneration period in air after irradiation. The spot diameter distribution obtained by the new ECE-method can be described by the sum of two curves of lognormal distribution, corresponding to the light and heavy fission tracks. (author)