Abstract: A method for data backup on magnetic tape including data restoring provides a sequence of functions such that for data backup the data which are stored in data files and memories are collected and transferred through a network interconnection to a data backup system and from there to a magnetic tape, wherein the data stream is continuously effected so that the data to be safeguarded do not undergo a temporary storage. The speed and reliability of data safeguarding is thus greatly increased. The sequence of functions for data restoring is the reverse of those for data backup.