Apparatus for rehabilitation of un upper limb of a person, said apparatus comprising: - a base frame; - a kinematic chain connected to said base frame, said kinematic chain comprising: - a plurality of rigid links connected in series one after the other between a first rigid link and a last rigid link, said first rigid link being operatively connected to said base frame; - a plurality of rotational joints each of which having a respective rotation axis and arranged to rotatably connect two successive rigid links of said series; said kinematic chain being configured in such a way that the rotation axes of the first 3 rotational joints starting from said first rigid link are arranged to intersect each other in a point C positioned, in use, at the centre C' of the shoulder articulation of the user; - a plurality of actuation groups, each actuation group of said plurality being associated to a respective rotational joint and being configured to generate and transmit a predetermined driving power to said rotational joint associated to it; - a detection group (171,172) configured to determine the angular position of each rotational joint of said plurality; - a fastening device configured to fasten the user's arm to at least a rigid link of said plurality; said apparatus being characterised in that said first rigid link is operatively connected to said base frame by means of a connection device configured to move from a connection configuration, in which said connection device is arranged to transmit a torque between said first rigid link and said base frame, to a release configuration, in which said first rigid link is free to rotate with respect to said base frame whereby no torque can be transmitted between said first rigid link and said base frame, when the user exerts, at said fastening device, a force such that the torque transmitted to said connection device is greater than a predetermined threshold value. - a base frame; - a kinematic chain connected to said base frame, said kinematic chain comprising: - a plurality of rigid links connected in series one after the other between a first rigid link and a last rigid link, said first rigid link being operatively connected to said base frame; - a plurality of rotational joints each of which having a respective rotation axis and arranged to rotatably connect two successive rigid links of said series; said kinematic chain being configured in such a way that the rotation axes of the first 3 rotational joints starting from said first rigid link are arranged to intersect each other in a point C positioned, in use, at the centre C' of the shoulder articulation of the user; - a plurality of rigid links connected in series one after the other between a first rigid link and a last rigid link, said first rigid link being operatively connected to said base frame; - a plurality of rotational joints each of which having a respective rotation axis and arranged to rotatably connect two successive rigid links of said series; - a plurality of actuation groups, each actuation group of said plurality being associated to a respective rotational joint and being configured to generate and transmit a predetermined driving power to said rotational joint associated to it; - a detection group (171,172) configured to determine the angular position of each rotational joint of said plurality; - a fastening device configured to fasten the user's arm to at least a rigid link of said plurality; said apparatus being characterised in that said first rigid link is operatively connected to said base frame by means of a connection device configured to move from a connection configuration, in which said connection device is arranged to transmit a torque between said first rigid link and said base frame, to a release configuration, in which said first rigid link is free to rotate with respect to said base frame whereby no torque can be transmitted between said first rigid link and said base frame, when the user exerts, at said fastening device, a force such that the torque transmitted to said connection device is greater than a predetermined threshold value.