The subject invention offers data deletion operation with respect to the area storing image data for security purpose, and also offers a function for suspending the deletion operation by a specific condition so as to accept a request of processing new image data. The image processing device includes image data inputting means for inputting image data; image data storing means for storing the image data inputted by the image data inputting means; image data processing (outputting) means for processing (outputting) the image data stored in the image data storing means; image data invalidating (deleting) means for performing invalidation (deletion) of the image data stored in the image data storing means; directing means for directing cutoff of the invalidation performed by the image data invalidating means; and permitting means for permitting the cutoff of the invalidation directed by the directing means.