A server includes a frame body, a fixed member and a circuit board. The fixed member is fixed on the side of the frame body, and includes a main structure, a stopper, a secure structure and an elastic secure-and-release structure. The main structure is bored with a hole. The stopper is disposed on the side of the main structure. The elastic secure-and-release structure is extended from the main structure to the hole and formed with a protrusion. The circuit board is formed with a notch, a key-shaped hole and a positioning hole. When the circuit board is assembled to the circuit board fixture, the notch is secured by the stopper, the key-shaped hole is provided for the secure structure being inserted therein, and the positioning hole is provided for the protrusion being inserted therein, so as to make the circuit board be fixed.