Constitution of Kenya
155. Principal Secretaries
(1) There is established the office of Principal Secretary, which is an office in the public service.
(2) Each State department shall be under the administration of a Principal Secretary.
(3) The President shall--
(a) nominate a person for appointment as Principal Secretary from among persons recommended by the Public Service Commission; and
(b) with the approval of the National Assembly, appoint Principal Secretaries.
(4) The President may re-assign a Principal Secretary.
(5) A Principal Secretary may resign from office by giving notice, in writing, to the President.