A microneedle array is provided which has (1) the strength to withstand insertion into the skin surface layer and/or stratum corneum, (2) the fineness and flexibility to cause no pain or bleeding in the skin surface layer and/or stratum corneum at the insertion site of the microneedles, and (3) solubility or biodegradability of the microneedle portions under the skin. The microneedle array is produced by forming microneedles using proteoglycan as a base material.