A method for detecting motion by way of a motion detection system comprising a radar apparatus which is in signal communication with a monitoring and control unit, said radar apparatus being configured to generate an electromagnetic signal suitable for illuminating a predetermined monitored space; said method being characterized in that it comprises the following steps: - performing at least one scanning cycle on said monitored space by means of said radar apparatus; - detecting and identifying at least one moving object (6, 7) in said monitored space, said step of detecting and identifying at least one moving object (6, 7) in said monitored space comprising the sub-step of detecting the actual displacement value for each moving object (6, 7) detected inside said monitored space between a detection cycle and the subsequent detection cycle; - providing a threshold value of maximum allowable displacement associated with every moving object (6, 7) detected inside said monitored space between a detection cycle and the subsequent detection cycle; - locating at least one semi-static zone in said monitored space, said step of locating at least one semi-static zone in said monitored space comprising the following sub-steps: - identifying at least one semi-static object which is moving in said monitored space having an actual displacement value equal to or less than said threshold value of maximum allowable displacement between a detection cycle and the subsequent detection cycle for a predetermined number of consecutive scanning cycles, - delimiting said semi-static zone as a localized volume of said monitored space in which said at least one semi-static object has moved during said predetermined number of scanning cycles; - generating an alarm signal only when in said monitored space at least one moving object (6, 7) situated outside said at least one semi-static zone is detected. - performing at least one scanning cycle on said monitored space by means of said radar apparatus; - detecting and identifying at least one moving object (6, 7) in said monitored space, said step of detecting and identifying at least one moving object (6, 7) in said monitored space comprising the sub-step of detecting the actual displacement value for each moving object (6, 7) detected inside said monitored space between a detection cycle and the subsequent detection cycle; - providing a threshold value of maximum allowable displacement associated with every moving object (6, 7) detected inside said monitored space between a detection cycle and the subsequent detection cycle; - locating at least one semi-static zone in said monitored space, said step of locating at least one semi-static zone in said monitored space comprising the following sub-steps: - identifying at least one semi-static object which is moving in said monitored space having an actual displacement value equal to or less than said threshold value of maximum allowable displacement between a detection cycle and the subsequent detection cycle for a predetermined number of consecutive scanning cycles, - delimiting said semi-static zone as a localized volume of said monitored space in which said at least one semi-static object has moved during said predetermined number of scanning cycles; - identifying at least one semi-static object which is moving in said monitored space having an actual displacement value equal to or less than said threshold value of maximum allowable displacement between a detection cycle and the subsequent detection cycle for a predetermined number of consecutive scanning cycles, - delimiting said semi-static zone as a localized volume of said monitored space in which said at least one semi-static object has moved during said predetermined number of scanning cycles; - generating an alarm signal only when in said monitored space at least one moving object (6, 7) situated outside said at least one semi-static zone is detected.