A separated-panel structure of a vehicle body panel including: a first panel, forming a part of an outer shape of a vehicle, including an outer face, a first flange face formed at the rear end of the outer face, and a second flange face formed an end of said outer face to face the trunk opening; a second panel, arranged at the rear of said first panel, including a first bottom face, a first wall face connected to said first bottom face and overlapping said first flange face, and a third flange face formed contiguously to said first wall face and overlapping said outer face, and a fourth flange face formed facing the trunk opening; and a third panel, arranged between a trunk opening and said first panel and between the trunk opening and said second panel, including a second wall forms as a part of an edge of the trunk opening, a third wall face overlapping said second flange face and said fourth flange face, a second bottom face connecting said second wall face and said third wall face, a fifth flange face formed by bending of said third wall face and overlapping said first wall face, and an extending section from said second bottom face toward said first bottom face and overlapping said first bottom face.