PROBLEM TO BE SOLVED: To provide an herbicide characterized by containing a benzoxazole derivative as an active ingredient. SOLUTION: This herbicide contains the benzoxazole derivative expressed by the following formula (1) (wherein, R1 to R4 are each H, a 1-6C alkyl, a 1-4C alkoxy, a 1-4C haloalkyl, a 1-4C haloalkoxy, a halogen atom, nitro, cyano or the like A is CHR5-Y, CR5=CR6, CR5CR7-CHR6 or CHR5 R5 is a 1-6C alkyl R6, R7 are each H, OH, a 1-6C alkyl or a halogen atom Y is O, S or NH and W is a heterocyclic ring) as the active ingredient.
