Provided is an image tagging device including: a first functional unit in which an image including an object that is a target of privacy protection is stored and that removes privacy information by changing part of the master image; a second functional unit that acquires the changed image from the first functional unit and changes a region image of an object that is not to be tagged in the first image; a function that distributes the changed image from the second functional unit to a tagging operation terminal device and receives image tag information from the tagging operation terminal device over a network; and a tagged image generator that generates a tagged image on the basis of the master image and the image tag information. This makes it possible to collect tagged images while achieving both privacy protection and an improvement in efficiency of a tagging operation.