ICP MASS SPECTROMETER

PROBLEM TO BE SOLVED: To provide an ICP mass spectrometer capable of improving efficiency of introduction to an opening of a skimmer cone.SOLUTION: A ICP mass spectrometer comprises: an interface section 20 disposed between a plasma ion source 10 and a mass spectrometer section; and a control section which controls the mass spectrometer section. The interface section 20 includes a chamber 21 and a vacuum pump for bringing the inside of the chamber 21 into a vacuum state. On a sidewall 21a of the chamber 21 at a side of the plasma ion source 10, a sampling cone 23 including an opening 23a is disposed and on a sidewall 21b of the chamber 21 at a side opposite to the side of the plasma ion source 10, a skimmer cone 24 including an opening 24a is disposed. Between the sampling cone 23 and the skimmer cone 24, an ion guide 25 is disposed and the control section controls a voltage to be applied to the ion guide 25.