The invention relates to a junction box. The junction box comprises a main body, a lower cover, one or more sockets, one or more connectors, a single connection bolt and a single connection nut; a circuit part is installed in the main body; the lower cover is constructed to cover the lower part of the main body; the one or more sockets are installed on the lower surface of the main body; the one or more connectors are installed in the lower cover, and constructed to be connected to the sockets; the single connection bolt is installed in the main body; and the single connection nut is installedin the lower cover, and is in threaded connection with the connection bolt. When the single bolt is rotatably operated, the main body is constructed to move upwardly or downwardly corresponding to the lower cover; and thus, the sockets can be connected to the connectors or disconnected from the connectors while performing upward/downward motion corresponding to the connectors.