In this paper we discuss some improvements in a new technique and inherent apparatus for preparation of thin foils. In the present version of the special electrolyzer used there is a more convenient separation of the rotary and floating motion between the cathode and the anode, motion which previously was confined only to the anode. With the rotating anode and the floating cathode it is possible to obtain maximum ease of operation and maximum control of the surface parallelism of the specimen being thinned. The measuring of residual thickness against time is also facilitated. The possibility of regulating the balancing force of the floating motion over a wide range starting from zero gives rise to another important variable in choosing the best thinning conditions and, in particular, permits the thinning of disks of smaller diameter. The most important technical improvement concerns the employment of electrochemically moulded cathodes with profiles rigorously conjugated with a perfectly flat anodic surface.