The present invention provides a nitrogen-containing saturated heterocyclic compound that is useful as a renin inhibitor/antagonist. A compound represented by formula [I] or a pharmaceutically acceptable salt thereof. (In the formula, R1 denotes a cycloalkyl group and the like, R22 denotes an optionally substituted aryl group and the like, R denotes a lower alkyl group and the like, T denotes a carbonyl group, Z denotes -O- and the like, and R3, R4, R5 and R6 may be the same or different and each denote a hydrogen atom and the like.)
