The present invention relates to a piperidine compound represented by the formula [I]: wherein Ring A represents an optionally substituted benzene ring, Ring B represents an optionally substituted benzene ring, R1 represents an optionally substituted hydoxyl group, a substituted thiol group, a substituted sulfonyl group, etc., or a group represented by the formula: R11 represents a substituted carbonyl group or a substituted sulfonyl group, R12 represents hydrogen atom or an optionally substituted alkyl group, R2 represents hydrogen atom, etc., Z represent oxygen atom or a group represented by —N(R3)—, R3 represents an optionally substituted alkyl group, etc., R4a represents an optionally substituted alkyl group, R4b represents an optionally substituted alkyl group, or a pharmaceutically acceptable salt thereof, having an excellent tachykinin receptor antagonistic action.