The synthesized crystalline ion exchange material or a hydrate thereof has a chain structure and a composition represented by the following general formula (A) in an anhydride form:xM.sub.2 O.ySiO.sub.2.zM'O, (A)wherein M represents Na and/or K; M' represents Ca and/or Mg; y/x is 0.5 to 2.0; and z/x is 0.005 to 1.0. The chain structure exhibits at least one main scattering peak at 970.+-.20 cm.sup.-1 in Raman spectra. The detergent composition contains the above synthesized inorganic crystalline ion exchange material. The inorganic ion exchange material of the present invention is excellent in both cationic exchange capacity and anti-solubility, making it useful to be used for a water softener and alkalinity regulator in detergents. The detergent composition of the present invention contains an inorganic ion exchange material which has anti-solubility as well as excellent ion exchange capacity and alkaline capacity, thereby offering excellent washing effects and is suitable for the concentration of detergent.