Beryllium is a light element having an atomin number of 4. Beryllium is not created during the familiar courses of nuclear reactions in the stars, but is primariliy created by spallation of heavier nuclei by cosmic rays. Beryllium is also created during the early cosmic nucleosynthesis, whose reaction rate is considered to reflect the baryon contents of the universe. Therefore the measurement of primeaval Beryllium is a key in understanding the composition of our universe and its fate.