An unmanned aircraft, comprising: a sensor that includes at least a microphone that generates sound data; and a processor, wherein the processor determines quality of a target sound using the sound data generated by the microphone, obtains a positional relationship between the unmanned aircraft and a sound source of the target sound using data generated by the sensor, and controls movement of the unmanned aircraft to control a distance between the unmanned aircraft and the sound source of the target sound, in accordance with the quality of the target sound and the positional relationship, characterized in that the processor further obtains distance information indicating a predetermined distance from the sound source by reading from a memory of the unmanned aircraft, when the quality of the target sound is lower than a predetermined goal quality, the processor causes the unmanned aircraft to approach the sound source, when causing the unmanned aircraft to approach the sound source, the processor controls the movement of the unmanned aircraft in accordance with the distance information and the positional relationship to cause the unmanned aircraft not to approach any closer to the sound source over a boundary of a safety area of the sound source, in a three-dimensional space, which is defined by the predetermined distance, and when the quality of the target sound is higher than the predetermined goal quality, the processor causes the unmanned aircraft to move in a horizontal direction away from the sound source and in a direction to approach ground, out of the safety area, to cause the unmanned aircraft to move to any position between a current position of the unmanned aircraft and a position at which the quality of the target sound reaches the predetermined goal quality, and the processor: further calculates a signal-to-noise (S/N) ratio using the target sound and noise related to flight of the unmanned aircraft, as an indicator for determining the quality, obtains, from the memory, a goal S/N ratio precalculated using the noise related to the flight of the unmanned aircraft, as the predetermined goal quality, and determines the quality of the target sound by comparing the goal S/N ratio obtained and the S/N ratio calculated. a sensor that includes at least a microphone that generates sound data; and a processor, wherein the processor determines quality of a target sound using the sound data generated by the microphone, obtains a positional relationship between the unmanned aircraft and a sound source of the target sound using data generated by the sensor, and controls movement of the unmanned aircraft to control a distance between the unmanned aircraft and the sound source of the target sound, in accordance with the quality of the target sound and the positional relationship, characterized in that the processor further obtains distance information indicating a predetermined distance from the sound source by reading from a memory of the unmanned aircraft, when the quality of the target sound is lower than a predetermined goal quality, the processor causes the unmanned aircraft to approach the sound source, when causing the unmanned aircraft to approach the sound source, the processor controls the movement of the unmanned aircraft in accordance with the distance information and the positional relationship to cause the unmanned aircraft not to approach any closer to the sound source over a boundary of a safety area of the sound source, in a three-dimensional space, which is defined by the predetermined distance, and when the quality of the target sound is higher than the predetermined goal quality, the processor causes the unmanned aircraft to move in a horizontal direction away from the sound source and in a direction to approach ground, out of the safety area, to cause the unmanned aircraft to move to any position between a current position of the unmanned aircraft and a position at which the quality of the target sound reaches the predetermined goal quality, and the processor: further calculates a signal-to-noise (S/N) ratio using the target sound and noise related to flight of the unmanned aircraft, as an indicator for determining the quality, obtains, from the memory, a goal S/N ratio precalculated using the noise related to the flight of the unmanned aircraft, as the predetermined goal quality, and determines the quality of the target sound by comparing the goal S/N ratio obtained and the S/N ratio calculated. further calculates a signal-to-noise (S/N) ratio using the target sound and noise related to flight of the unmanned aircraft, as an indicator for determining the quality, obtains, from the memory, a goal S/N ratio precalculated using the noise related to the flight of the unmanned aircraft, as the predetermined goal quality, and determines the quality of the target sound by comparing the goal S/N ratio obtained and the S/N ratio calculated.