An environmental testing apparatus includes: a plurality of blower fans that circulate air-conditioned air between an air conditioning chamber and a test chamber; a plurality of temperature sensors that measure temperature at a plurality of locations in the test chamber and output temperature data; and a control unit that can individually set rotation speed of each blower fan. The control unit executes setting processing for setting the rotation speed of each blower fan in a testing period in a setting period before the testing period. In the setting processing, the control unit changes the rotation speed of the plurality of blower fans a plurality of times, and acquires a plurality of temperature data after each change from the plurality of temperature sensors.