PURPOSE: To improve guarantee assurance of continuous injection by reducing friction resistance at the time of piercing of a needle through a rubber septum, by making a needle of a microsyrings sharp conical shape and providing an ejecting hole on cylinder section of the needle.

CONSTITUTION: A micro-syringe 18 is mounted on an automatic specimeninjecting device driving unit 16, and specimen of a sample holder 20 is injected into an atomizing chamber 24 of rubber septum type. The specimen is analyzed by a gas chromatograph 22, and the data are accumulated in a data processing device 28. A cylindrical rodlike needle 30 of the micro-syringe 18 has a sharp conical tip, and an ejecting hole 32 is provided on outside circumferential surface of the cylindrical section in such a manner as to be connected to a hollow section. It is possible, by doing so, to extremely reduce friction resistance at the time when tip of the needle of the micro-syringe 18 pierces the rubber septum, keep the needle 30 from being bent, maintain the ejecting hole 32 perpendicular to axial direction of the needle 30 and prevent rubber of the hole 32 from breaking and producing fragment at the time of piercing of the needle, and therefore, it is possible to improve guarantee assurance of continous injection and also to prevent occurrence of ghost peak at the same time.