Abstract: A probe comprises a support casing, a movable arm-set with an arm carrying a feeler and a detection device providing a signal further to contact occurring between the feeler and the workpiece. In order to enable the feeler to perform translation displacements along a longitudinal geometrical axis and rotations about transversal axes, the matching between the support casing and the arm-set is obtained by means of a cone-shaped surface, a spherical surface and a spring urging these surfaces into contact. An annular reference surface of the movable arm-set enters into contact with an annular plane surface of the support casing when a first eccentricity value of the feeler, with respect to the longitudinal geometrical axis, is reached, and when a second eccentricity value is reached the signal of the detection takes a determined value.