A roof structure includes: horizontal base materials forming a roof slope; and roof panels fixed on the horizontal base materials and spread side by side in a slope direction, each of the roof panels includes a roofing board, and rafters fixed to a lower surface of the roofing board in parallel to each other, and extending perpendicularly to the horizontal base materials, each of the rafters of one of the two adjacent roof panels in the slope direction includes a carry-out portion projecting from an edge of the roofing board, each of the carry-out portions being between the rafters of the other roof panel and fixed to the roofing board of the other roof panel, a projection length of the carry-out portions is smaller than a distance between the adjoining horizontal base materials, and the carry-out portions and the other roof panel are fixed to the same horizontal base material.