To provide a method that efficiently separates HFO-1234yf and CTFE from a mixture including 2,3,3,3-tetrafluoro propene (HFO-1234yf) and chlorotrifluoroethylene (CTFE).

A method of manufacturing HFO-1234yf includes a process in which an azeotrope-like composition consisting of 23-91% by mol of HFO-1234yf and 77-9% by mol of CTFE, and an initial mixture including HFO-1234yf and CTFE in which a content of HFO-1234yf in the total amount thereof exceeds 49% by mol are distilled to be separated into a first fraction in which a content of HFO-1234yf in the total amount of HFO-1234yf and CTFE is lower than that of the initial mixture, and a second fraction in which a content of HFO-1234yf in the total amount of HFO-1234yf and CTFE is higher than that of the initial mixture, whereby HFO-1234yf in which a concentration of CTFE is lowered is obtained from the second fraction.