A parasite control agent or parasiticide that has an exceptional effect for controlling or exterminating parasites, especially endoparasites, and that can be safely used contains as an active ingredient at least one selected from compounds represented by formula (I) or salts thereof. (In formula (I), Cy represents a heteroaryl group or the like； X represents a halogeno group or the like； n is any integer of 0-5； when n is 2 or higher, the X may be the same as or different from each other； R1 represents an optionally substituted C1-6 alkyl group or the like； A represents a nitrogen atom or the like； R2, R3, and R4 each independently represent a hydrogen atom, optionally substituted C1-6 alkyl group, or the like； and R5 represents an optionally substituted C6-10 aryl group, optionally substituted heteroaryl group, or the like.)
