During a jet spinning method, the rotating fibre ends or the subsequent wound fibres of the spun yarn (70) cause a spinning tension Fs. In tests, a direct correlation has been established between the spinning result and the spinning tension Fs. The aim of the invention therefore is to provide a method for spinning yarn in a jet spinner that permits an ideal spinning tension Fs despite high spinning speeds, thus achieving an optimal spinning result, in particular with regard to the yarn quality. According to the invention, a jet spinner is operated with a spinning tension Fs