To provide an unmanned aircraft collecting device using a shock-absorbing balloon capable of avoiding any damage of an unmanned aircraft, reducing the number of damages, and simultaneously preventing any peripheral ware from being damaged when collecting the unmanned aircraft if any sufficient gliding and landing area is not available.

The unmanned aircraft collecting device 15 mounted on an unmanned aircraft 1 comprises a balloon 7 which is inflated by the gas flowing therein, a gas cylinder 10 for flowing out the gas to inflate the balloon 7, an air tube 9 forming a flow passage in which the gas flows from the gas cylinder 10 into the balloon 7, a solenoid valve 8 which is provided in the middle of the flow passage, and prevents the gas from flowing in the balloon 7 from the gas cylinder 10 by maintaining the closed state, and allows the gas to flow into the balloon 7 from the gas cylinder 10 by being changed to the opened state from the closed state if the solenoid valve opening signal for instructing the opened state is input, and a controller 11 which sets the solenoid valve 8 in the closed state to the opened state by generating the solenoid valve opening signal and outputting it to the solenoid valve 8.