In the present invention, an applicator (A) pierces skin (S) with a microneedle (32), and thereby moves an active component into a body through the skin (S). The applicator (A) is provided with a piston board (20) having a first protrusion (33) and second protrusions (20d1-20d4) provided on the lower side of one main body (20a). The surface of the first protrusion (33) has the microneedles (32) disposed thereon. The second protrusions (20d1-20d4) are disposed around the first protrusion (33) set apart from the first protrusion (33).本發明之微型針施作器(A)，是藉由微型針(32)對皮膚穿刺，用以使活性成分透過皮膚移轉至體內的物品。微型針施作器(A)，是具備活塞板(20)，該活塞板(20)是於一方的本體(20a)的下表面側設有：突出部(33)、以及突出部(20d1~20d4)。於突出部(33)的表面，配置有微型針(32)。突出部(20d1~20d4)，是與突出部(33)在間隔開的狀態下，被配置在突出部(33)的周圍。
