An information processing device to communicate with a plurality of personal terminals possessed by a plurality of different possessors, each of the plurality of personal terminals being configured to acquire first data indicating a result of inputting whether a corresponding one of the possessors is comfortable, second data indicating a terminal location, and third data indicating a temperature at the terminal location, the information processing device comprising: a first learning unit configured to classify the plurality of personal terminals into a plurality of classes based on the first to third data transmitted from the plurality of personal terminals; a storage unit configured to store a plurality of control details each associated with a corresponding one of the plurality of classes into which the first learning unit classifies the plurality of personal terminals; and a control unit configured to read, from the storage unit, a control detail associated with a class into which a personal terminal detected in an air conditioning target space is classified among the plurality of classes and control an air conditioning device, characterized in that the first learning unit is configured to classify the plurality of personal terminals based on an index indicating comfort computed from the first to third data, for each of the plurality of classes, a comfort range of the index indicating that the possessors are comfortable is defined, and when the plurality of personal terminals each belonging to a corresponding one of the plurality of classes are detected in the target space, the control unit controls the air conditioning device to cause, when the target space is air-conditioned, the index to fall within a range common to the plurality of comfort ranges each associated with a corresponding one of the plurality of classes. a first learning unit configured to classify the plurality of personal terminals into a plurality of classes based on the first to third data transmitted from the plurality of personal terminals; a storage unit configured to store a plurality of control details each associated with a corresponding one of the plurality of classes into which the first learning unit classifies the plurality of personal terminals; and a control unit configured to read, from the storage unit, a control detail associated with a class into which a personal terminal detected in an air conditioning target space is classified among the plurality of classes and control an air conditioning device, characterized in that the first learning unit is configured to classify the plurality of personal terminals based on an index indicating comfort computed from the first to third data, for each of the plurality of classes, a comfort range of the index indicating that the possessors are comfortable is defined, and when the plurality of personal terminals each belonging to a corresponding one of the plurality of classes are detected in the target space, the control unit controls the air conditioning device to cause, when the target space is air-conditioned, the index to fall within a range common to the plurality of comfort ranges each associated with a corresponding one of the plurality of classes.