A safety fence used in a field of a construction work includes a guide rail disposed parallel to an outer wall of a building being constructed. A fence frame is disposed to cover the outer wall and movable along the guide rail and an elevating device for moving the fence frame along the guide rail provided. A tent is disposed on the fence frame. A net for reinforcing the tent may be fixedly disposed on the fence frame. The fence frame includes a plurality of platforms that are vertically connected to each other in a multi-story structure. The platforms are connected to each other by braces.