An electronic structure calculation program based on the density functional theory and the pseudo potential scheme with a plane wave basis set. This is a powerful tool to predict the physical properties of unknown materials and to simulate experimental results such as STM and EELS. This also enables users to perform long time molecular dynamics simulations and to analyze chemical reaction processes. This program is available on a wide variety of computers from single-core PCs to massive parallel computers like K computer. The whole source code is open to public.