To provide a drain pipe suitable for a culvert drain pipe having an antifouling effect to suppress the darkening of the pipe or the pollution of accumulated water.

A drain pipe comprises: a cylindrical inner layer made of a thermoplastic resin; and an outer layer formed of one or two or more strand-shaped articles wound in a direction to intersect the axial direction of the cylindrical inner layer. An inorganic antibacterial agent is blended in at least the cylindrical inner layer. In a preferable mode of the drain, an inorganic antibacterial agent belongs to a silver group inorganic antibacterial agent.