PURPOSE:To simplify construction of a batten seam roof structure and increase the water resistance of the structure by covering with a roofing plate a bed on which square timber is affixed, and also covering the roofing plate with a cap body having a spatula-shaped portion, and laying and sticking a sheet member thereon. CONSTITUTION:A bed 2 on which square timber 1 forming a batten seam roof 1 is affixed is covered with a roofing plate 4 and a wrapping plate 5, and a cap body 6 which is made from a weather-proofing hard resin and which has a spatula-shaped portion 6a is also covered thereon. A sheet member 8 made of a rubber material is laid over the spatula-shaped portion 6a and stuck thereto by an adhesive 7. The batten seam roof with excellent water resistance can thus be obtained.