Abstract: In a digital signal reproducing apparatus for detecting identifying data in a reproduced digital data signal which had been recorded on slant tracks formed sequentially on a magnetic tape by a rotary head and which is reproduced at a speed higher than a normal playback speed, a synchronizing detector circuit detects synchronizing data included in the reproduced digital signal and, in response thereto, a pulse signal is generated and supplied to an identifying data detector circuit which, in response to such pulse signal, receives a plurality of corresponding identifying data. The identifying data detector circuit determines the identifying data value which corresponds to the majority of the received plurality of identifying data.