The low-temperature electronic structure of the quarter-filled, quasi-one-dimensional (Q1D) system (DI-DCNQI)2Ag is revealed using synchrotron radiation x-ray diffraction. In spite of the interchain frustration in the twofold superstructure along the 1D chain, the body-centered tetragonal "charge ordering" structure, which consists of 4k_{F} charge ordering columns and 4k_{F} bond order wave columns, is realized. This is the first example of the Q1D system having plural kinds of columns as its ground state. This charge ordered structure is regarded as a Wigner crystal caused by intercolumn Coulomb repulsion.