An exoskeleton device arranged to assist the movement of the phalangeal articulations (50,60) of a thumb finger, said exoskeleton device arranged to pass between an open configuration and a closed configuration during the rotations θ 1,θ 2 of said phalangeal articulations (50,60), said exoskeleton device comprising: - a metacarpal support arranged to be integral to a metacarpal portion of a hand; - a first support having engagement means arranged to engage said first support to a first phalanx of said thumb finger; - a kinematic chain arranged to connect said metacarpal support and said first support; said kinematic chain comprising: - a linear actuator constrained to said metacarpal support by a first spherical joint and arranged to carry out a stroke x; - a first stiff link connected to said linear actuator by a first universal joint; - a second stiff link connected to said metacarpal support by a second universal joint and connected to said first stiff link by a first rotational joint; - a second auxiliary stiff link connected to said second stiff link by a second rotational joint; - a first slide connected to said first support and arranged to carry out a translation with respect to it along an axis y, said first slide being also connected to said first stiff link by a second spherical joint; said first slide and said second spherical joint being configured for avoiding the generation of forces parallel to said axis y on said first phalanx of said thumb finger, when said exoskeleton device passes between said open configuration and said closed configuration, said exoskeleton device characterized in that it comprises a second support having engagement means arranged to engage said second support to a second phalanx of said thumb finger and in that said kinematic chain comprises furthermore: - a third stiff link connected to said second auxiliary stiff link by a third universal joint; - a fourth stiff link connected to said third stiff link by a fourth universal joint and connected to said first stiff link by a fifth universal joint; - a second slide connected to said second support and arranged to carry out a translation with respect to it along an axis y', said second slide being connected to said fourth stiff link by a third spherical joint; said second slide and said third spherical joint being configured for avoiding the generation of reactions parallel to said axis y' on said second phalanx of said thumb finger, when said exoskeleton device passes between said open configuration and said closed configuration. - a metacarpal support arranged to be integral to a metacarpal portion of a hand; - a first support having engagement means arranged to engage said first support to a first phalanx of said thumb finger; - a kinematic chain arranged to connect said metacarpal support and said first support; - a linear actuator constrained to said metacarpal support by a first spherical joint and arranged to carry out a stroke x; - a first stiff link connected to said linear actuator by a first universal joint; - a second stiff link connected to said metacarpal support by a second universal joint and connected to said first stiff link by a first rotational joint; - a second auxiliary stiff link connected to said second stiff link by a second rotational joint; - a first slide connected to said first support and arranged to carry out a translation with respect to it along an axis y, said first slide being also connected to said first stiff link by a second spherical joint; said first slide and said second spherical joint being configured for avoiding the generation of forces parallel to said axis y on said first phalanx of said thumb finger, when said exoskeleton device passes between said open configuration and said closed configuration, said exoskeleton device characterized in that it comprises a second support having engagement means arranged to engage said second support to a second phalanx of said thumb finger and in that said kinematic chain comprises furthermore: - a third stiff link connected to said second auxiliary stiff link by a third universal joint; - a fourth stiff link connected to said third stiff link by a fourth universal joint and connected to said first stiff link by a fifth universal joint; - a second slide connected to said second support and arranged to carry out a translation with respect to it along an axis y', said second slide being connected to said fourth stiff link by a third spherical joint; said second slide and said third spherical joint being configured for avoiding the generation of reactions parallel to said axis y' on said second phalanx of said thumb finger, when said exoskeleton device passes between said open configuration and said closed configuration. - a third stiff link connected to said second auxiliary stiff link by a third universal joint; - a fourth stiff link connected to said third stiff link by a fourth universal joint and connected to said first stiff link by a fifth universal joint; - a second slide connected to said second support and arranged to carry out a translation with respect to it along an axis y', said second slide being connected to said fourth stiff link by a third spherical joint;