To reliably control a vapor pressure and a cloth speed so that they take efficient and optimum values, while restricting a vapor consumption amount to a least necessary amount in a continuous cylinder dryer for drying a wet cloth to be dried.

In a cloth continuous cylinder dryer 2, a control device 20 is constructed so that the control device 20 can repeat a following detecting, calculating and controlling operations at a given interval. Namely, a total drying moisture content Wo and a control drying moisture content Wc are calculated in response to an inlet moisture content We of a cloth to be dried and a predetermined cloth speed Vs which have been detected by an inlet moisture sensor 4 and cloth speed sensor, 5 respectively. A total reference drying ability Pwo and a control reference drying ability Pwc are calculated from drying characteristics of the cylinder dryer 2. The ratio between the control drying moisture content Wc and the control reference drying capacity Pwc, namely, the drying capacity ratio Dr is obtained. An optimum vapor pressure Po and an optimum cloth speed Vo which correspond to this drying capacity ratio Dr is calculated. A vapor pressure P fed to respective heating cylinders 3 is controlled to the optimum vapor pressure Po, while a cloth speed V is controlled to the optimum cloth speed Vo simultaneously. With such a coupled use of the vapor valve control and the cloth speed control, an energy saving effect and an enhancement of productivity are simultaneously achieved.