A window blind apparatus 1 includes a plurality of slats 4 juxtaposed in a vertical direction Z between a pair of vertical frames 2 and 3 which oppose each other in a lateral direction X; pairs of foldable link mechanisms 5 connecting the plurality of slats 4 to each other; a pair of raising/lowering mechanisms 6 for raising or lowering the plurality of slats 4 in the vertical direction Z; and a pair of tilt mechanisms 7 for tilting the plurality of slats 4 by causing pairs of front edge link members 34 and 35 and pairs of rear edge link members 44 and 45 of the respective link mechanisms 5 to undergo relative positional change.