Abstract: An analytical microsyringe includes a syringe body, an injection needle fixed to the inner surface at one end of the syringe body, a linear plunger formed of superelastic wire and a knob integrally fixed to the rear end of the linear plunger. The linear plunger has the front end thereof formed to have a diameter large enough to tightly and slidably contact the inner surface of the syringe body and a portion thereof other than the large-diameter front end formed to have a smaller diameter and keep clear of the inner surface of the syringe body.