A tonometer for continuously monitoring the arterial blood pressure of a patient for a predetermined period of time, said tonometer comprising: - a bracelet configured in such a way to be applied to a wrist of a patient; - a detection group mounted on said bracelet and configured for detecting a pressure signal, said detection group comprising a plurality of pressure sensors arranged to detect a respective pressure signal associated to the blood pressure wave of the patient, at least a pressure sensor of said plurality being positioned, in use, in proximity of the radial artery of the patient, at the opposite side of the radial bone; - a touching group interposed, in use, between said detection group and said radial artery of said patient, said touching group equipped with a plurality of protuberant members (65a-65d), each said protuberant member (65a-65d) of said plurality arranged to be positioned, in use, into contact with the skin of said patient, in such a way to exert a predetermined force F on said radial artery and to transmit the received pressure pulses to a respective pressure sensor associated to it; - a processing unit arranged to process said pressure signal detected by said detection group in such a way to determine the blood pressure wave of the patient; wherein said touching group is made of a predetermined material having an elastic constant greater than elastic constant of the radial artery, wherein said touching group comprises a base portion that is integral, in use, to said detection group and a plurality of connection portions (63a-63d) each of which arranged to elastically connect a respective protuberant member (65a-65d) to said base portion, wherein each said connection portion (63a-63d) of said plurality comprises a plurality of connection arms (64a,64b,64c) configured in such a way to have a controlled elastic flexibility along a predetermined direction (165a-165d) substantially orthogonal to said base portion such that, each protuberant member (65a-65d) of said plurality is suitable to elastically move along said direction substantially orthogonal to said base portion, characterized in that said connection arms (64a,64b,64c) are substantially S-shaped, each of said connection arms (64a,64b,64c) being configured in such a way to lay, in a rest position, on a plane orthogonal to said movement direction (165a-165d) of said protuberant members (65a-65d). - a bracelet configured in such a way to be applied to a wrist of a patient; - a detection group mounted on said bracelet and configured for detecting a pressure signal, said detection group comprising a plurality of pressure sensors arranged to detect a respective pressure signal associated to the blood pressure wave of the patient, at least a pressure sensor of said plurality being positioned, in use, in proximity of the radial artery of the patient, at the opposite side of the radial bone; - a touching group interposed, in use, between said detection group and said radial artery of said patient, said touching group equipped with a plurality of protuberant members (65a-65d), each said protuberant member (65a-65d) of said plurality arranged to be positioned, in use, into contact with the skin of said patient, in such a way to exert a predetermined force F on said radial artery and to transmit the received pressure pulses to a respective pressure sensor associated to it; - a processing unit arranged to process said pressure signal detected by said detection group in such a way to determine the blood pressure wave of the patient;