At the beginning of a new Parliament, the President of the Senate appoints the members of the Select Committees, taking into account the size of parliamentary groups.

The Committee on Rules comprises ten senators and is chaired by the President of the Senate. It considers and introduces changes to the Rules of Procedure and issues opinions on the interpretation of the Rules submitted to it by the President of the Senate.

The Committee for Elections and Parliamentary Immunity is composed by nineteen senators, its chairperson being elected from among its members. It checks credentials and reasons for disqualification. This Committee also examines requests by the judiciary for authorisation to conduct personal or house searches on senators, to arrest senators, wire-tap their conversations or communications and impound their correspondence. It also examines requests to prosecute ministers.