To provide a building shutter device which is constituted to prevent the wind-thickening of a winding drum in a fully open attitude of a shutter curtain, while forming the shutter curtain from slats different in shape from one another.

The shutter curtain 2 is formed from the general closing slat 6, and the slat 7 for ventilation, in which a large number of through-holes 7d for ventilation and daylighting are opened. In this case, the slat 7 is provided at the lower end of the shutter curtain 2; and the number of the coupled slats 7 is set to fall within a range in which the slats 7 different in shape are not put into a laminated state, in a state in which the shutter curtain 2 in the fully open attitude is wound around the winding drum 4.