PURPOSE: To enable the measurement of a sample dissolved in a solvent using the SIMS method by spraying the sample, jetting it from a narrow hole, forming it into a molecular-line type sample, introducing it into a high vacuum chamber that is set to the degree of specific vacuum through the narrow hole section such as a skimmer that is exhausted differentially, and making it collide against a metal plate.

CONSTITUTION: A sample solution dissolved in a solvent that is sequentially separated by a liquid chromatograph device 1 is jetted as a molecular-line type sample 3 through an atomizer 2 with a nozzle of 10μm in diameter, for example. The sample solution is sprayed to this atomizer 2 from the nozzle using an ultrasonic vibrator. The molecular-line type sample 3 starting from the atomizer 2 is introduced into an ionized chamber 5 that is kept in high vacuum of 10-5 to 10-6 Torr through a single or a number of heated skimmers 4 and collides against a metal target 6 made of silver plate and such provided in the ionized chamber. The sample adhesion surface section of the target 6 is irradiated with a primary ion beam 7 with an inclination of 20 degrees against the surface of the target 6.