In the method of manufacturing the outer cylinder with needle, the needle tube 3 is inserted into the needle insertion hole 41 of the thermoplastic resin outer tube 2, and the base end portion 31 of the needle tube 3 is inserted into the outer cylinder And the melt fixing process is performed. In the melting and fixing step, energy is applied to the needle tube 3 at a portion positioned on the distal end side from the proximal end of the needle insertion hole 41 and the proximal end of the needle tube to cause the needle tube 3 to generate heat, whereby the needle positioned in the heat generating portion By melting the inner surface forming resin of the insertion hole 41 and causing the molten resin to flow downward in the needle insertion hole 41 to fill the gap between the needle tube 3 and the outer surface of the proximal end portion of the needle tube 3.針付き外筒の製造方法では、針管3が熱可塑性樹脂製外筒2の針挿入孔41に挿入し、かつ、外筒2が起立した状態にて、針管3の基端部31を外筒に溶融固着する溶融固着工程を行う。溶融固着工程は、針挿入孔41の基端および針管の基端より、先端側に位置する部分にて、針管3にエネルギーを付与し、針管3を発熱させることにより、発熱部に位置する針挿入孔41の内面形成樹脂を溶融させ、溶融樹脂を針挿入孔41内を下方に流下させ、針管3の基端部外面との間の空隙を埋めることにより行う。
