Environmental test apparatus

An environmental test apparatus that can create a predetermined environment inside a test chamber, the environmental test apparatus comprising:

• the test chamber for placing a test target object;
• a heating portion;
• and
• a cooling portion, wherein
• the cooling portion has a refrigeration circuit having a compressor, a condenser, an expansion portion, and an evaporator and in which a phase-changing refrigerant is to be circulated,
• the refrigeration circuit has a first bypass flow path connecting a discharge side of the condenser and a suction side of the compressor and the first bypass flow path is provided with a first flow rate control portion,
• a temperature measurement portion for measuring a temperature of the compressor and a controller are provided, and
• the controller is configured to control an inside of the test chamber to the predetermined environment and is configured to control a substantial degree of opening of the first flow rate control portion according to a detection value of the temperature measurement portion.