To provide a ventilation ridge mounting structure of a shed roof which enables a ventilation ridge B to be mounted on the shed roof A stably and firmly, can prevent the flow of rainwater from the eaves direction on a roof material other than a rising part 1a even if the ventilation ridge B is arranged on the rising part 1a of the shed roof A, enables the attachment of shed ridges E, E on right and left sides of the ventilation ridge B by a coping 13, and cannot only secure draft by the ventilation ridge B but can also protect the shed roof A part on the right and left sides of the ventilation ridge B from rainwater by both the shed ridges E, E.

The ventilation ridge B is mounted to the shed roof A by a mount 3 and a top-part support 4. The ventilation ridge B has a ventilation route C and an offtake 8d which are extended from the vicinity of the top of the shed roof A of a building to the eaves direction side along the inclined surface of the roof.