PURPOSE: To improve dome opening and closing performance together with weathering performance near the top of a dome and reliability by disposing a movable roof in an inclined annular rail path, and taking the central top part or the top part of a projected arc part of the movable roof superposed on the recessed arc part of a fixed roof as the center of rotation on a line inclined to a vertical line.

CONSTITUTION: A dome roof is formed by a fixed roof 1 and a movable roof 5 rotated to be superposed on the fixed roof 1, the movable roof 5 is disposed in an inclined annular rail path 22, a projected arc part 6 provided on the movable roof 5 is superposed on a recessed arc part 2 provided on the fixed roof 1, and the central top part of the projected arc part 6 of the movable roof 5 is taken as the center 8 of rotation on a line (b) inclined (α) to a vertical line (a). In an opening and closing dome, the movable roof 5 is formed by two movable roofs 15a, 15b, and the top parts of the projected arc parts 16a, 16b of the respective movable roofs 15a, 15b are taken as the center 8 of rotation on a line (b) inclined (α) to a vertical line (a).