PROBLEM TO BE SOLVED: To efficiently remove paper powder contained in liquid chemicals and reuse the liquid chemicals for the production of sanitary tissue paper.SOLUTION: A method of producing sanitary tissue paper containing liquid chemicals comprises: a step of supplying the liquid chemicals reserved in a service tank 11 to an application device 12; a step of applying the liquid chemicals onto a base paper of the sanitary tissue paper by the application device 12; a step of collecting the excess liquid chemicals supplied to the application device 12 into a buffer tank 13; a step of separating the excess liquid chemicals collected in the buffer tank 13 into the liquid chemicals and the paper powder by a separation device 14; and a step of supplying the liquid chemicals separated by the separation 14 to the application device 12 or another application device.
