To provide a cleaning device on a tank in a granule carrying vehicle wherein in the first, a burden for a worker is sharply reduced, in the case of leaning work on the tank, by dispensing with the need for holding a cleaning hose by hand to go up/down a ladder also in the second, the cleaning hose is excellent in its durability and cost.

This cleaning device 9 is provided with an air piping 10 connected to a pressure air source C, interposition piping 11 connected a base end to the air piping 10 and a tip end to an air intake port 15 in a lower end part of a vertical pipe 13 of a ladder 12, the vertical pipe 13 of the ladder 12 provided with an air take out port 17 in an upper end part to connect between the air take out port 17 and the air intake port 15, and a cleaning hose 14 connected a base end to the air take out port 17 in the vertical pipe 13 of the ladder 12 to be arranged on a tank 2. In this way, cleaning work is performed by a worker, with the hose 14 on the tank 2.