In order to provide a compound that shows a strong effect on controlling a plant disease, a triazole compound of the present invention (i) is a compound in which -OH group,-R2 group, and CH2-Ar group are bonded in cis configuration with a cyclopentane, (ii) is (-)- enantiomer or (+) enantiomer, and (iii) is represented by Formula (I):(wherein R1 represents an alkyl group R2 represents a haloalkyl group and Ar represents a substituted/unsubstituted aromatic hydrocarbon group or a substituted/unsubstituted aromatic heterocyclic group.