A server includes a power module, a detection circuit, a switching circuit, at least one first electric component and at least one second electric component. The power module supplies a standby voltage under a standby mode and supplies a working voltage under a working mode. The detection circuit receives a working mode signal of the server to output a control signal. The working mode signal specifies that the server is under the standby mode or the working mode. The switching circuit is supplied with the working voltage, the standby voltage and a converted control signal generated by converting the control signal, to transfer either the working voltage or the standby voltage. The first electric component works under the working mode only. The second electric component works under the standby mode and the working mode.