A building method of an immobilization device (1) applicable to at least one body segment of a patient to at least partially immobilize it. Said method comprising the following steps:detecting the volumetric dimensions of the patients body segment setting the shaping of said immobilization device (1) printing said immobilization device (1) using a 3D printer, said 3D printer comprising at least one pair of nozzles for the emission of materials having different physical characteristics so as to vary, area by area, the physical characteristics of said device immobilization (1).
