An inspection apparatus (100) according to an aspect of the present invention includes a first determination unit (121) that determines an operation of an unmanned aerial vehicle (1) based on a first threshold for determining whether the unmanned aerial vehicle (1) can enter the inside, a second threshold, which is greater than the first threshold, for determining whether the unmanned aerial vehicle (1) can land on a water surface of pooled water in the inside, and space information indicating a space of the inside, and a second determination unit (122) that determines a flight altitude of the unmanned aerial vehicle (1) with respect to the water surface or a floor surface of the manhole after the unmanned aerial vehicle (1) enters the inside based on the first and second thresholds, and the space information in a case where it has been determined that the unmanned aerial vehicle (1) can enter the inside and cannot land on the water surface.