Answer: Six
The six principal organs of the UN are the General Assembly, Security Council, Economic and Social Council, Trusteeship Council, International Court of Justice and UN Secretariat. One of these, the Trusteeship Council, was formally suspended in 1994 when its purpose was regarded as fulfilled. It had been established to oversee the administration of certain dependent territories, but when the last of these territories became independent, the Council no longer had a role. It cannot be dissolved without amending the UN Charter, however, so is simply regarded as inactive.