§1. In regard to the suitability of a candidate for the episcopacy, it is required that he is: 1/ outstanding in solid faith, good morals, piety, zeal for souls, wisdom, prudence, and human virtues, and endowed with other qualities which make him suitable to fulfill the office in question; 2/ of good reputation; 3/ at least thirty-Five years old; 4/ ordained to the presbyterate for at least Five years; 5/ in possession of a doctorate or at least a licentiate in sacred scripture, theology, or canon law from an institute of higher studies approved by the Apostolic See, or at least truly expert in the same disciplines.
§2. The definitive judgment concerning the suitability of the one to be promoted pertains to the Apostolic See.
Source: Code of Canon Law (Vatican.va)