A controlling device for an air environment regulating system which air environment regulating system comprises a regulating device that is configured to regulate an air environment of an indoor space which includes an air quality, a measuring device configured to measure the air environment of the indoor space, and an evaluating device configured to output feeling information reflecting a result of evaluating a degree of comfort with regard to the air environment of the indoor space by one or more persons-in-room, the regulating device including one or more ventilators (21, 22, 23) for causing a movement of air between the indoor space and an outdoor space, and the measuring device being configured to measure an air environment of the outdoor space in addition to the air environment of the indoor space, wherein the evaluating device includes an input unit configured to allow the one or more persons-in-room in the indoor space to input information regarding the feeling information, and is configured to output the feeling information indicative of the information inputted into the input unit, or wherein the evaluating device includes:a history storage unit configured to store one or more records each of which includes a combination of the measurement information, the control information, and the feeling information and added each time the control information is changed; andan estimating unit configured to estimate the feeling information from a combination of the measurement information and the control information with reference to the one or more records stored in the history storage unit, and is configured to output the feeling information indicative of a result of estimation by the estimating unit; wherein the controlling device is configured to generate control information for controlling the regulating device and wherein the controlling device comprises: an obtaining unit configured to obtain measurement information with regard to the air environment of the indoor space measured by the measuring device, and an operation determining unit configured to generate the control information by modifying, with the feeling information, basic information derived from the measurement information; characterized in that the basic information is for operating the regulating device, the basic information being information indicative of a relationship between a condition indicative of a combination of the measurement information obtained from the measuring device and a condition indicative of desired operation of the regulating device, in that the controlling device is configured to provide the basic information to the regulating device, thereby instructing the regulating device to start operation, the controlling device being configured to be allowed to receive the feeling information from the evaluating device after a lapse of predetermined time from a time when the regulating device starts to operate in accordance with the basic information, in that a time period from a time of providing the basic information to a time of allowing reception of the feeling information is set to an extent that the air environment of the indoor space is made to be stable by operation of the regulating device, wherein the time period is a fixed value that is different depending on an activity history of the one or more persons-in-room, and in that the controlling device being configured to generate the control information by modifying the basic information with the received feeling information. the controlling device is configured to generate control information for controlling the regulating device and wherein the controlling device comprises: an obtaining unit configured to obtain measurement information with regard to the air environment of the indoor space measured by the measuring device, and an operation determining unit configured to generate the control information by modifying, with the feeling information, basic information derived from the measurement information; an obtaining unit configured to obtain measurement information with regard to the air environment of the indoor space measured by the measuring device, and an operation determining unit configured to generate the control information by modifying, with the feeling information, basic information derived from the measurement information; characterized in that the basic information is for operating the regulating device, the basic information being information indicative of a relationship between a condition indicative of a combination of the measurement information obtained from the measuring device and a condition indicative of desired operation of the regulating device, in that the controlling device is configured to provide the basic information to the regulating device, thereby instructing the regulating device to start operation, the controlling device being configured to be allowed to receive the feeling information from the evaluating device after a lapse of predetermined time from a time when the regulating device starts to operate in accordance with the basic information, in that a time period from a time of providing the basic information to a time of allowing reception of the feeling information is set to an extent that the air environment of the indoor space is made to be stable by operation of the regulating device, wherein the time period is a fixed value that is different depending on an activity history of the one or more persons-in-room, and in that the controlling device being configured to generate the control information by modifying the basic information with the received feeling information.