A power device suited for being assembled in a chassis and connected with a plug is provided. The power device includes a housing, and a receptacle, a spring clamp, a position limiting element disposed on the housing. The plug is removably connected to the receptacle. The spring clamp has a moving end. The position limiting element is located between the spring clamp and the receptacle. The position limiting element and the moving end of the spring clamp are linked together to move between a first position and a second position relative to the housing. When the plug connects to the receptacle, the position limiting element is interfered with the plug and the spring clamp simultaneously so that the spring clamp is constrained at the first position.