To improve the ventilation property of a space between a tile and a roof substrate in a laid state.

In this plate tile, a recess 6 is formed in a part below a valley part 3 of a tail-side part of an undersurface of a tile body 1 in such a shape as to reach a tail-side end surface of the tile body 1 by setting the flow-direction width of the recess 6 greater than that of a crossrail S. When the plate tile is laid, the recess 6 makes a ventilation passage formed between the undersurface of the tile body 1 and the crossrail S, so that air can be easily circulated in the flow direction of the space below the tile.