A method of controlling the duration of a drying phase of a process for cleaning and optionally disinfecting items to be cleaned, comprising the following steps: a) measuring a relative humidity value of an exhaust air humidity at at least two times t i different from each other by using a first humidity sensor, b) measuring the temperature of exhaust air that flows out of a cleaning chamber in which the items to be cleaned are dried, by means of a first temperature sensor, c) calculating absolute humidity values from the measured relative humidity values and the measured temperature so that the at least two values for the exhaust air humidity each indicate an absolute humidity of the exhaust air, d) measuring a relative humidity value of a supply air humidity at the same times t i by using a second humidity sensor, wherein in addition the temperature of supply air, which is at least partly sucked in from an environment of the cleaning chamber and is used for drying the items to be cleaned, is measured by means of a second temperature sensor, e) calculating absolute humidity values from the measured relative humidity values and the measured temperature so that the at least two values for the supply air humidity each indicate an absolute humidity of the supply air, (f) calculating, on the basis of at least two values of the absolute humidity of the exhaust air and the at least two values of the absolute humidity of the supply air, a time period expected to be required for a difference between the absolute humidity of the exhaust air and the absolute humidity of the supply air to fall below a specifiable threshold value; and g) terminating the drying phase when the time period has elapsed. a) measuring a relative humidity value of an exhaust air humidity at at least two times t i different from each other by using a first humidity sensor, b) measuring the temperature of exhaust air that flows out of a cleaning chamber in which the items to be cleaned are dried, by means of a first temperature sensor, c) calculating absolute humidity values from the measured relative humidity values and the measured temperature so that the at least two values for the exhaust air humidity each indicate an absolute humidity of the exhaust air, d) measuring a relative humidity value of a supply air humidity at the same times t i by using a second humidity sensor, wherein in addition the temperature of supply air, which is at least partly sucked in from an environment of the cleaning chamber and is used for drying the items to be cleaned, is measured by means of a second temperature sensor, e) calculating absolute humidity values from the measured relative humidity values and the measured temperature so that the at least two values for the supply air humidity each indicate an absolute humidity of the supply air, (f) calculating, on the basis of at least two values of the absolute humidity of the exhaust air and the at least two values of the absolute humidity of the supply air, a time period expected to be required for a difference between the absolute humidity of the exhaust air and the absolute humidity of the supply air to fall below a specifiable threshold value; and g) terminating the drying phase when the time period has elapsed.