To produce the subject molecular sieve useful as a catalyst for a selective oxidation process such as olefin epoxidation process, by allowing a reactant mixture containing supply sources of Si, Sn, an organic template additive, Ti, Ge, F, or the like, respectively to react at a specified pH, at a sufficient temperature for a sufficient time.

The production process for the molecular sieve comprises: forming a reactant mixture which contains supply sources of Si, Sn and an organic template additive, respectively, and further optionally contains supply sources of Ti, Ge, a fluoride and hydrogen peroxide, respectively; and allowing the reactant mixture to react at sufficient temperature for a sufficient time to produce a crystalline molecular sieve. In the production process, the reactant mixture preferably has a composition (molar ratios) represented by the expression SnO2:aR2O:bSnO2:cGeO2:dTiO2:eF:fH2O2:gH2 O [wherein: R is an organic template additive; (a) is a numerical value of 0.06-0.5; (b) is a numerical value of 0.001-0.1; (c) is a numerical value of 0-0.08; (d) is a numerical value of 0-0.1; (e) is a numerical value of 0.1-2; (f) is a numerical value of 0-0.5; and (g) is a numerical value of 4-50] and also, the crystalline molecular sieve has an X-ray diffraction pattern characteristic of a zeolite β-structure.