A server includes an enclosure, a motherboard, and first and second switches. The enclosure includes a base and a cover. The first switch is used to manually turn on or off the motherboard. The second switch is capable of turning off the motherboard and is mounted on a sidewall of the base. A stopping piece extends down from one side of the cover to abut against the second switch. The second switch is connected to a power-on pin of the motherboard. When the cover is not covering the base, the stopping piece fails to abut against the second switch. And the second switch is turned off. The power-on pin receives a power-off signal to power off the server.