A direct solid sampling technique based on continuous powder introduction and coupled with microwave induced plasma optical emission spectrometry (CPI-MIP-OES) is presented. The sampling system is designed on the basis of the fluidized bed concept. Plasma diagnostics was performed to assess the analyte vaporization capacity of the MIP. The rotational temperature and the ionization temperature attain up to 3500K and 7500K, respectively. However, matrix effects caused by inorganic and organic samples are significantly different. Moreover, differences in vaporization efficiency are possible between surface impurities and bulk traces. The method is easily applicable for the determination of relatively volatile elements in materials of particle size below 80µm. The analytical potential of the CPI-MIP-OES is shown during the reliable analysis of some industrial and environmental materials. The single calibration graph approach based on powdered reference materials was adequate for determination of Cu, Mg, Si and Zn (DLs around 100 ng g^-1) in Al₂O₃, SnO₂, La₂O₃ and MgO of spectrographic grade. Major amounts of Co, Mo, V and Ni were determined in alumina and silica based catalysts using external calibration with both matrix and particle size matching. The CPI technique and helium MIP was applied for the determination of fluorine (DL of 3-6 µg g^-1) in geological materials. The CPI-MIP-OES is attractive when coupled with the SPE technique. Analytes are introduced to the plasma as analyte-on-sorbent particles. The method was used for determination of metals and fluoride in water and precious metals in geological materials.