A triazole derivative or pharmaceutically acceptable salt thereof is provided, the triazole derivative being represented by formula (I): wherein * represents an asymmetric carbon and takes R configuration or S configuration; and R1 represents a structure represented by formula (II) or (III): represents single bond or double bond wherein Y represents a hydrogen atom or an oxygen atom; and R2 and R3 each independently represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a formyl group, a carboxyl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an amino group, an alkylcarbonylamino group, an arylcarbonylamino group, a cyano group, a nitro group or a halogen atom.