PURPOSE: To facilitate the automation of the coupling work by suppressing the drift and backlash of the coupling portion of a louver device.

CONSTITUTION: The first claws 32a, 32b of a cell plate 24 are inserted into the first coupling hole 30 of a shade frame 23, and the second claws 33a, 33b are inserted into the second coupling holes 31a, 31b. Jigs Z1, Z2 faced downward from above the shade frame 23 are pressed to cell plate center side faces 32c of the first claws 32a, 32b and cell plate end section side faces 33c of the second claws 33a, 33b. The first claws 32a, 32b and the second claws 33a, 33b are folded in the approaching direction to each other.