PROBLEM TO BE SOLVED: To reduce the physical load on an agricultural work by applying an agrochemical in the process of a seeding work with a seeder to simplify the applying work, when the agrochemical to be applied on the seeding is used. SOLUTION: This granular substance-applying device for a seeder, is characterized by comprising a receiving case 10 which is used for receiving an agrochemical and disposed above a seedling-raising box C during being carried, and a tubular nozzle portion 20 communicating with the receiving case 10, wherein the nozzle portion 20 is disposed below the receiving case 10 and above the seedling-raising box C during being carried, and an outlet for flowing out the agrochemical flowed down from the receiving case 10 by the gravity is disposed on the lower side corresponding to the seedling-raising box C.
