An object of the present invention is to provide an antifungal agent which has excellent antifungal effects and is superior in terms of its physical properties, safety and metabolic stability. According to the present invention, there is disclosed a compound represented by the following formula (I), or a salt thereof: wherein R1 represents a hydrogen atom, a halogen atom, an amino group, a C1-6 alkyl group, a C1-6 alkoxy group or a C1-6 alkoxy C1-6 alkyl group; R2 represents a hydrogen atom, a C1-6 alkyl group, an amino group or a di C1-6 alkylamino group; one of X and Y is a nitrogen atom while the other is a nitrogen atom or an oxygen atom; ring A represents a 5- or 6-member heteroaryl ring or a benzene ring which may have a halogen atom, or 1 or 2 C1-6 alkyl groups; Z represents a single bond, a methylene group, an ethylene group, an oxygen atom, a sulfur atom, —CH2O—, —OCH2—, —NH—, —CH2NH—, —NHCH2—, —CH2S—, or —SCH2—; R3 represents a hydrogen atom, a halogen atom, a C1-6 alkyl group, a C3-8 cycloalkyl group, a C6-10 aryl group, a 5- or 6-member heteroaryl group, or 5- or 6-member non-aromatic heterocyclic group which may have 1 or 2 substituents; and R4 represents a hydrogen atom or a halogen atom.