Disclosed is a process for producing 2-chloro-1,3,3,3-tetrafluoropropene (1224), including a first step of separating 2,3-dichloro-1,1,1,3-tetrafluoropropane 234da) into erythro form and threo form, and a second step of bringing the separated erythro form or threo form in contact with a base to obtain 2-chloro-1,3,3,3-tetrafluoropropene (1224). The first step is a step of separating 234da by
distillation to achieve a separation into a fraction containing mainly erythro form and a fraction containing mainly threo form. In the second step, 1224 cis form is obtained from the erythro form, and 1224 trans form is obtained from the threo form. By this process, it is possible to selectively and efficiently produce cis form or trans form of 2-chloro-1,3,3,3-tetrafluoropropene (1224).