Abstract: An information sharing support device supports sharing of a plurality of pieces of sharing target information related to the development and the manufacture of a manufacturing target apparatus, the information sharing support device including: a tagging unit for attaching a tag selected from a plurality of tags to each of the plurality of pieces of sharing target information; and a sharing target information managing unit for managing the plurality of pieces of sharing target information in association with each other on the basis of the tag attached to each of the plurality of pieces of sharing target information, wherein the plurality of pieces of sharing target information includes basic sharing target information and additional sharing target information that is additionally input to the basic sharing target information by a staff member at a manufacturing site of the manufacturing target apparatus, and a tag attached to the additional sharing target information includes a tag attached to the basic sharin