Microneedle device is provided, which include microneedles that can be easily inserted into skin and dissolve or swell in skin. The microneedle devices comprise a substrate and cone-shaped or pyramid-shaped microneedles for skin insertion set on the substrate. The microneedles for skin insertion contain over 50 weight percent of one or multiple biomaterials chosen from chitosan, collagen, gelatin, hyaluronic acid, and they are fabricated from the materials that can dissolve or swell in the body.