The present invention is a method for producing a single crystal, the method in which, after a charging process, a crucible position setting process including a step of placing a lower end of a conical valve below a lower end of a purge tube, a step of performing a movement in such a way that the conical valve and the crucible get relatively closer to each other while measuring changes in the weight of the conical valve, a step of detecting contact between the lower end of the conical valve and an upper end of a raw material based on the rate of change in the weight of the conical valve, a step of measuring the position of the upper end of the raw material based on the position of the lower end of the conical valve at which the contact was detected, and a step of setting the position of the crucible so that the spacing between the lower end of the purge tube and the upper end of the raw material charged in the crucible becomes a predetermined distance and a melting process including a crucible position adjusting step of adjusting the position of the crucible so that the spacing between the lower end of the purge tube and the upper end of the raw material maintains a predetermined distance in accordance with the progress of melting of the raw material are performed. As a result, it is possible to perform control so that the spacing between the lower end of the purge tube and the upper end of the raw material charged in the crucible becomes a predetermined distance.