To provide a metallic core material-filled eave gutter, in which the buckling phenomenon of the base section of the eave gutter due to the temperature rise of the base section can be avoided for preventing the deterioration of quality in the eave gutter after the execution of works.

In a metallic core material 4-filled eave gutter, in which inner and outer surfaces are coated with a synthetic resin 2, a boundary between a base section and a residence-side side face section is formed in a curved surface section 1 smoothly bulged in the external direction. The thickness of the layer of the synthetic resin 2 on the outer surface of the base section is made larger than that of the layer of the synthetic resin 2 on the inner surface of the base section.