Which body is responsible for appointing judges?

Answer 1

The U.S. Constitution created the U.S. Supreme Court, and it gave Congress the power to set up lower federal courts. Congress did that starting back in 1789 with the Judiciary Act. We have the U.S. Court of Appeals, with 11 "circuits" and the "D.C. Circuit" also. And we have many U.S. District Courts, which are the trial-level courts for civil and criminal matters.

All of the judges for these courts are appointed by the President and must be approved of (or "confirmed") by the Senate. Once appointed and confirmed, they have a lifetime appointment. They can keep their jobs as long as they want to, regardless of public opinion or the shifting alliances of politics in America.

P.S. I don't think the above is true for federal "Magistrate" judges. They are lower-level judges that handle pre-trial litigation issues. They hold hearings and issue rulings in federal courts. They're real judges, with both skills and power that deserve respect. But they're not the Constitutional Article III judges that have to be appointed by the President and confirmed in the Senate.

Answer 2

If the judge occupies an appointive position, (i.e.: NOT elected by popular vote) they are usually named by the Executive Branch of the government and confimred by the Legislative Branch.