We propose a new method to quantify particulate sodium and potassium salts (nitrate, chloride, and sulfate) by using a refractory aerosol thermal desorption mass spectrometer (rTDMS). The combination of a graphite particle collector and a carbon dioxide laser enables high desorption temperature. Laboratory experiments showed that major ion signals originating from sodium or potassium salts were clearly detected, associated with the increase in the desorption temperature by laser heating.