Judge Claude Jorda of France cited permanent ill health as the reason for his departure, which will take effect in August.
The president of the ICC, Judge Philippe Kirsch, expressed his regret and in a statement thanking Judge Jorda “for his service and for his commitment to fulfilling his obligations before leaving the court”.
Judge Jorda presided in the pre-trial case against Thomas Lubango Dyilo, a former militia leader from the Democratic Republic of the Congo, who is accused of recruiting child soldiers. On January 29, he confirmed there was sufficient evidence on all three counts for the case to proceed to trial.
Lubanga is the only suspect in ICC custody. No trial date has yet been set.
Judge Jorda also served at the International Criminal Tribunal for the Former Yugoslavia from 1994, and in 1999 became president of the tribunal.
He was actively involved in establishing and implementing the procedures currently used at the tribunal and is credited with pushing through reforms aimed at streamlining often lengthy trials.
The Assembly of States Parties to the ICC, which currently has 104 members, will elect a judge to fill the vacancy when it meets at the end of this year.
There are a total of 18 judges from around the world serving at the ICC.
Sara Goodman is an IWPR reporter in The Hague.