A test apparatus applicable to a server includes a processing unit, a control unit, a switch unit and a power relay unit. The processing unit outputs a reset signal and a processing signal. The control unit includes a first physical layer chip performing a first communication protocol, and a second physical layer chip performing a second communication protocol. The switch unit receives a working voltage and a processing signal to select a powering signal or a disconnection signal to output. The power relay unit receives the powering signal or the disconnection signal. When the power relay unit receives the powering signal, the server performs a test task on the first physical layer chip. When the power relay unit receives the disconnection signal and the processing unit outputs the reset signal to the control unit, the server performs the test task on the second physical layer chip.