To provide a valley part structure capable of using a valley gutter board capable of suppressing amount of used material and to provide a valley covering member capable of improving efficiency of construction of the valley part structure.

The valley gutter board 104 is provided on valley faces 103a, 103b of two inclined rooves 101a, 101b having different ridge directions, and oblique-cut faces 105a, 105b are brought close to parts above both side parts of the valley gutter board to tile the rooves with oblique-cut valley tiles 107a, 107b. Next, the valley covering member 50 is laid on the oblique-cut valley tiles through a caulking material. The valley covering member is composed of a main body having a plane covering the oblique-cut valley tiles and formed into substantially an arrow splashed pattern and a three-dimension structural body capable of being attached to a short width part of the main body. When the valley covering member is laid on the oblique-cut tiles, a head part concealing part of the three-dimension structural body conceals a head part of the oblique-cut valley tile.