The present invention relates to a method for fabricating an aptamer-coated, microneedle-based diagnostic skin patch and a patch fabricated thereby. A patch of the present invention has the advantage of attaching a great number of aptamers, which are much smaller in size than antibodies, onto a relatively great number of microneedle tip surfaces, Allowing the attachment of aptamers for various kinds of biomarkers all together thereto, the patch can also simultaneously detect various kinds of materials (multiplexing). Therefore, a microneedle tip-based skin patch can also be used as a protein chip using aptamer.