Federal Court of Justice of Germany
Only one year later, Scharen was appointed as judge at the Federal Court of Justice of Germany, where he was assigned to the 10th division (German: "X. Zivilsenat"), of which he was since 2004 the division's deputy. This division mainly handles patent law and public procurement cases. On 1 April 2009 Scharen was finally appointed chairman of this division by the President of Germany, on a proposal of the Presidium of the Federal Court of Justice. On 31 August 2010 he retired.