To process an edge of a hole of a deposition part formed by galvanic deposition as a flawless clear edge.

A method for fixing a decoration (1) to an external timepiece element (2) coated with an electrically deposited metallic layer (3) is provided. Instead of the decoration (1), a dummy (5) is temporality placed on a hole (4) pieced in the external element (2), and electrical deposition (3) is carried out. After leveling the deposition part, the dummy part (5) is removed and the decoration is placed in the hole (4).