In this paper, “metallomics” is proposed as a new scientific field in order to integrate the research fields related to biometals. Metallomics should be a scientific field in symbiosis with genomics and proteomics, because syntheses and metabolic functions of genes (DNA and RNA) and proteins cannot be performed without the aid of various metal ions and metalloenzymes. In metallomics, metalloproteins, metalloenzymes and other metal- containing biomolecules are defined as “metallomes”, in a similar manner to genomes in genomics as well as proteomes in proteomics. Since the identification of metallomes and the elucidation of their biological or physiological functions in the biological systems is the main research target of metallomics, chemical speciation for specific identification of bioactive metallomes is one of the most important analytical technologies to establish metallomics as the integrated bio-metal science. In order to rationalize the concept of metallomics, the distributions of the elements in man, human blood serum and sea-water, a challenge to all-elements analysis of one biological cell, and some other research topics are introduced with emphasis on recent development of chemical speciation of trace metals in some biological samples.