The power to appoint the Chief Justice lies with the President, who makes the selection from a list of three nominees prepared by the Judicial and Bar Council. There is no material difference in the process of selecting a Chief Justice from that in the selection of Associate Justices. As with the other Justices of the Supreme Court, the Chief Justice is obliged to retire upon reaching the age of 70, otherwise there is no term limit for the Chief Justice. In the 1935 constitution, any person appointed by the president has to be confirmed by the Commission on Appointments; in the 1973 constitution, the person whom the president has appointed won't have to go confirmation under the Commission on Appointments.
The Constitution does not ascribe any formal role to the Chief Justice other than as an ex-officio Chairman of the Judicial and Bar Council and as the presiding officer in any impeachment trial of the President. The Chief Justice is also required to personally certify every decision that is rendered by the Court. He or she carries only 1 vote out of 15 in the Court, and is generally regarded, vis-a-vis the other Justices, as the primus inter pares rather than as the administrative superior of the other members of the Court.
Still, the influence a Chief Justice may bear within the Court and judiciary, and on the national government cannot be underestimated. In the public eye, any particular Supreme Court is widely identified with the identity of the incumbent Chief Justice, hence appellations such as "The Fernando Court" or "The Puno Court". Moreover, the Chief Justice usually retains high public visibility, unlike the Associate Justices who tend to labor in relative anonymity, with exceptions such as Associate Justice J. B. L. Reyes in the 1950s to 1970s.
By tradition, it is also the Chief Justice who swears into office the President of the Philippines. One notable deviation from that tradition came in 1986, and later again in 2010. Due to the exceptional political circumstances culminating in the People Power Revolution, on February 25, 1986, Corazon Aquino took her oath of office as President before then Associate Justice Claudio Teehankee in San Juan just minutes before Ferdinand Marcos took his own oath of office also as President before Chief Justice Ramon Aquino. Marcos fled into exile later that night. More than two decades afterwards, Benigno Simeon Aquino III followed in his mother's footsteps (with almost similar reasons) by having then Associate Justice Conchita Carpio-Morales (now the incumbent Ombudsman) swear him in, rather than then Chief Justice Renato Corona (who was eventually impeached halfway through Aquino's term). 6 years later, in 2016, Rodrigo Duterte was sworn into office by Associate Justice Bienvenido Reyes, his classmate at San Beda College of Law, instead of Chief Justice Maria Lourdes Sereno.
And the Chief Justice is the chief executive officer of the Philippine Judiciary system and together with the whole Supreme Court, exercises administrative supervision over all courts and personnel.
