The invention concerns a USB-key type electronic device (73) comprising an electronic circuit mounted on a support (60), a gripping element showing a graphic print and/or customization (p), a protective case (70) arranged at the element so as to cause the graphic print and/or customization to be visible through the case. The invention is characterized in that the graphic print and/or customization is produced on the support (60) bearing the electronic circuit, and in that the case covers directly said support (60). The invention also concerns a method including the following steps: producing an electronic circuit support in the form of a printed smart card with contacts in conformity with the USB standard, producing a graphic customization on a support surface, protecting said graphic customization with a transparent protective shell.