A lipid membrane structure containing an anti-membrane-type matrix metalloproteinase monoclonal antibody such as an anti-MT1-MMP monoclonal antibody as a component of the lipid membrane structure. Said structure can be utilized as a drug delivery system for efficiently delivering a medicinally active ingredient and/or a gene to tumor cells, neoplastic vessel and the like in which a membrane-type matrix metalloproteinase (MT-MMP) is expressed.