To provide a process for producing ethylene and/or propylene at high selectivity.

Ethylene and/or propylene is produced by allowing a hydrogen carbonate material containing at least one linear 4-8C olefin and at least one branched 4-8C olefin to come into contact with a catalyst including zeolite and/or a zeolite analogous compound having pores of at least 8 or more-membered oxygen ring with a diameter (Di) of the largest bounding sphere, which can be present in the pore, of <0.630 nm.