An alkyl phenyl sulfide derivative represented by the general formula [I] or an agriculturally acceptable salt thereof, and a pest control agent containing the derivative or the salt as an active ingredient. [in the above formula, R 1 is, for example, a C 1 ˆ¼C 6 alkyl group which is mono- or poly-substituted with halogen atom； R 2 is, for example, a halogen atom or a C 1 ˆ¼C 6 alkyl group； R 3 is, for example, a hydrogen atom or a halogen atom； and R 4 is, for example, a hydrogen atom or a C 1 ˆ¼C 12 alkyl group.] The derivative or the salt has an excellent pest control effect.
