An object of the present invention is to efficiently inject a drug (physiologically active substance). Therefore, a micro-needle device 1 comprises a base plate 2 and a micro-needle 3 installed on the base plate 2. A coating agent containing the physiologically active substance is coated at least at a part of the micro-needle 3, and a coating range thereof is 100 to 230 μm including the top of the micro-needle 3. A load due to the energy of 0.2 to 0.7 J/cm2 is applied to the micro-needle device 1 which is in contact with the skin.
