The seat of the Court is at the Peace Palace in The Hague (Netherlands), but the Court is not prevented "from sitting and exercising its functions elsewhere whenever it desirable." (Art. 22). The Court’s role is to settle, in accordance with international law, legal disputes submitted to it by States and to give advisory opinions on legal questions referred to it by authorized United Nations organs and specialized agencies.

The ICJ was established in June 1945 by the UN Charter and began working in April 1946. Its Statute is part of the UN Charter. The Court shall be composed of a body of 15 independent judges. Its official languages are English and French.

The Court shall be open to the states parties to the present Statute. Only states may be parties in cases before the Court. The Court cannot be seized by individuals or by international entities or organizations. The General Assembly and the Security Council may ask the Court for advisory opinions on any legal question. Other organs of the UN and other institutions may do so, with the authorization of the General Assembly.

As in all cases when it comes to "supreme bodies", the question that makes one wonder is: who will be in position to choose these 15 magistrates and what are the principles to be respected in their choice? The 1st chapter of its Statute exposes the ICJ organization and addresses this issue  starting by Art. 4: "The members of the Court shall be elected by the General Assembly and by the Security Council from a list of persons nominated by the national groups in the Permanent Court of Arbitration," in accordance with the provisions listed there.

Leaving aside for the moment all the details and what the Permanent Court of Arbitration is, let us review some elements concerning the election of these 15 members of the ICJ. 

Three months before the date of the election, the UN Secretary-General shall address a written request to the members of the Permanent Court of Arbitration inviting them to undertake the nomination of candidates (Art. 5). Only two shall be of the same nationality of the group that presents them and the number of candidates shall not exceed the double of seats to be filled.

The Secretary-General shall prepare a list in alphabetical order of all the nominated persons and these shall be the only persons eligible. One exception if provided in Art. 12.2: "If the joint conference is unanimously agreed upon any person who fulfills the required conditions, he may be included in its list." The Secretary-General shall submit this list to the General Assembly and to the Security Council.  

What raises concern, however, is the weight granted in No. 2 of Art. 7 - "The Secretary-General shall submit this list to the General Assembly and to Security Council"- and in Art. 8 - "The General Assembly and the Security Council shall proceed independently of one another to elect the members of the Court"-, assimilating in so far the Security Council to the General Assembly. In fact, in Art. 10.1 it concludes: "Those candidates who obtain an absolute majority of votes in the General Assembly and in the Security Council shall be considered as elected."

The five permanent members of the Security Council, as we know, have the right to veto any decision of the same Council. That this Security Council also has such weight in the elections of the members of the Supreme Court of Justice does not seem to be in favor of either absolute independence or complete equanimity in the final decisions of the Court. Above all because Art. 9 states: "At every election, the electors shall bear in mind not only that the persons to be elected should individually possess the qualifications required, but also that in the body as a whole the representation of the main forms of civilization and of the principal legal systems of the world should be assured." Who will be responsible for establishing which are these "great civilizations" and "the main legal systems of the world"? The Art. 31 endeavors to correct imbalances by establishing the principle that in any ICJ judgment must have equal representation of the nationalities of the parties in the conflict. This same effort already reveals that everything does not seem perfectly correct. For more details and the salaries of these magistrates see on the UN website, Statute of the International Court of Justice