A capacitor seat and two conductors are utilized to install a capacitor seat on a PCB by soldering the two conductors on electrical contacts of the PCB. The capacitor is installed on the capacitor seat in a fastening way such as by pressing downward, rotating the capacitor or in other feasible fastening ways to be electrically connected with the electrical contacts on the PCB. If the detachable capacitor device has errors or is damaged in use, or a user wants to replace it with a different type of the capacitors to test or adjust the characteristic of the circuit, it is easy to replace the capacitor.