An apparatus (100) for sequentially analyzing particles such as single cells or single beads, by spectrometry. The apparatus, an elemental flow cytometer, includes means (102) for sequential particle introduction, means (104) to vaporize, atomize and excite or ionize the particles, or an elemental tag associated with an analyte on the particles, and means (106) to analyze the elemental composition of the vaporized, atomized and excited or ionized particles, or an elemental tag associated with the particles. Methods for sequentially analyzing particles such as singe cells or single beads by spectrometry are also described.