Abstract: The invention relates to a protective device adapted to be mounted at the base of a roof. The device has a set of posts each having a base section which locates in the gutter at the base of the roof and a fixing device linked to this base section, at least two arms being linked with a pair of posts, by upper parts and lower parts mounted on the posts, at least two bracing wires with each of these bracing wires being linked to one of the posts to connect it to a respective anchoring element located on the roof and a net connected to at least one of the arms and to two of the posts.