Abstract: A multiple solid phase microextraction (m-SPME) thermal desorption ionization device which desorbs an analyte and moves it into an entry of a mass spectrometer for mass spectrometry analysis is provided. The device has a charge producing unit, a heating unit and a sampling unit. The sampling unit provides a plurality of probes. The analyte is attached to the probes, and then the probes are inserted through a passage of the heating unit to instantly vaporize the analyte for ionization and analysis in conjunction with the charge producing unit and the mass spectrometer. Thus, the time needed for analyte analysis is shortened. A mass spectrometer system having the thermal desorption ionization device and an analytical method for mass spectrometry are also provided.