A pathogen detection apparatus includes a collector that collects a pathogen in air; a reactor that causes the pathogen collected by the collector to react with a labeled substance; a time measurer that measures time from start of reaction in the reactor; a detector that detects a quantity of labeled substance that has reacted with the pathogen; and a controller. The controller calculates a gradient value on the basis of a predetermined time period from the start of reaction measured by the time measurer and the quantity of labeled substance detected by the detector, and determines, on the basis of the gradient value, a time interval to next collection that is to be performed by the collector.