A drum type drying/washing machine performs drying without the flow of cooling water during a predetermined period of time or a period of time determined in accordance with an amount of clothes. After the passage of the period of time, the machine starts the flow of the cooling water so as to perform drying with cooling-dehumidication. The drum type drying/washing machine, at the initial stage of the drying operation, also performs not only the heating of clothing, but also the rotating of a drum at a high speed to dehydrate the clothing. A drum type drying/washing machine rotates a drum at an almost a maximum rotational rate at which, in a low speed rotation, materials to be processed can roll over in the drum; or at a rotational rate above which, in the low speed rotation, the materials to be processed as a whole stick to the inner peripheral wall of the drum. Further, the drum is accelerated to a high speed rotation only when an output from an unbalance detecting device is a predetermined level or less.