To improve utilization efficiency of raw materials of a fluid to be sprayed.

A spray mechanism includes a spray nozzle 10 spraying the fluid 20 to a spray area from a spray port 13 and an opening part 31 into which the spray port 13 is inserted and is provided with a partition plate 30 to separate a spray nozzle 10 side and a spray area side opposed thereto from the spray port 13 and a sidewall plate 40 extending toward the spray area side from the vicinity of the opening part 31 of the partition plate 30 with a predetermined angle with respect to the axial direction of the spray nozzle 10. The sidewall plate 40 is arranged outside of the spray area of the spray nozzle before the convergence in a condition that the partition plate 30 and the sidewall plate 40 are not arranged. When the fluid 20 is sprayed from the spray nozzle 10, the spray area is converged to the sidewall plate 40 side by making the outside air flow in to the spray area before convergence from an opposed side to the sidewall plate 40 side.