We demonstrate that fast anodic etching of bulk crystalline substrates of n-InP via photolithographically defined windows leads to the formation of nanomembranes and nanowires being promising for device applications. It is shown that, under potentiostatic etching conditions, the morphology of etched samples strongly depends on the applied voltage. We found that anodization at 5-7 V results in the formation of highly porous layers with mechanically stable skeletons exhibiting percolation, which easily detach from the substrate thus representing nanomembranes. At the same time the predominant formation of nanowires was evidenced at further increase of the applied voltage up to 15 V. Uniform deposition of Au dots on InP nanowires and nanowalls is demonstrated using electroplating.