There is no variation in the degree of scraping of the stratum corneum, chemical liquid can be supplied to the desired to depth position in the skin, and to provide a transdermal administration device that will not give a sense of fear to the patient. A housing 2 that the lower surface of the skin side is open, is disposed in the housing 2, and the lower surface from the projecting downward immersive possible locking member 4 into the housing 2 of the housing 2 is disposed in the housing 2, the housing 2 a movable needle holder 1 in the direction along the lower surface, the locking member 4 when a retracted into the housing 2, by the locking of the locking member 4 is disengaged, and I along the needle holder 1 on the bottom surface of the housing 2 and biasing means 31 for moving in the direction, which is a percutaneous administration device provided with a. Projecting needle 11 is downward from the lower surface of the needle holder 1, the lower surface of the needle holder 1 has the chemical liquid impregnated member 17 is provided.角質層の掻き取りの程度にばらつきがなく、薬液を皮内の所望とする深度位置に供給でき、かつ患者に恐怖感を与えることのない経皮投薬装置を提供する。皮膚側の下面側が開口するハウジング2と、ハウジング2内に配設され、ハウジング2の下面より下方へ突出しハウジング2内へ没入可能なロック部材4と、ハウジング2内に配設され、ハウジング2の下面に沿った方向へ移動可能な針保持部1と、ロック部材4がハウジング2内へ没入した際に、ロック部材4のロックが外れることにより、針保持部1をハウジング2の下面に沿った方向へ移動させる付勢手段31と、を備える経皮投薬装置である。針保持部1の下面より針11が下方へ突出し、針保持部1の下面に薬液含浸部材17が設けられている。
