The present invention provides a microneedle array which makes it possible to quantitatively and accurately inject a drug into the skin.The present inventors have found that when a microneedle array is coated with a drug composition comprising a drug and an additive which has a Vickers hardness of about 3 or more, the removal of the drug can be avoided, and the drug can be surely inserted into the skin along with the microneedle array. As a result, the microneedle array coated with the drug composition of the present invention can be used in the fields in which the drug is required to be administrated with high quantitative performance even when the drug is contained in small amounts, e.g., the administration of a vaccine, and the scope of application of the microneedle array can be extended.