DATA PROTECTION SYSTEM

PURPOSE:To execute data protection with a simple system without lowering the operatability of a system by transferring the data inside of an editing program to an auxiliary storage device after one editing processing is ended. CONSTITUTION:An external storage device 26 for storing a control program, document data and a temporary editing data backup, and an auxiliary storage device (DRAM or a non-volatile memory) 22 which stores temporary editing data are provided. An editing program 11 transfers and stores the editing data to the auxiliary storage device 24 at a prescribed timing when one editing processing is ended, and on the other hand, a storage program 14 stores the saved data of the auxiliary storage device 24 to the external storage device 26 at a prescribed interval asynchronously from the editing program 11. Thus, for a computer processor such as a word processor, the loss of the data is prevented at comparatively low cost without lowering the operability of the system, in preparation for an unexpected occurrence such as light failure during operation, etc.