Abstract: In order to carry out interventions, particularly for inspection and maintenance purposes, within heat exchangers, such as the steam generators equipping nuclear power stations, a device is proposed, which has an articulated arm formed from at least two rigid segments (24a, 24b), which are articulated to one another about an axis (A), as well as two plates (30a, 30b) mounted at the ends of the articulated arm via two handles (28a, 28b), each authorizing two rotations about two orthogonal axes (B, C), whereof one (B) is parallel to axis (A) and the other (C) is perpendicular to the surface (31a, 31b) of the corresponding plate. Each plate (30a, 30b) carries fastening members (32) able to engage in perforations (20a) of a tube plate (12) of the exchanger, as well as a support (34) for an intervention tool.