The connector includes a connector housing having two terminal fittings and terminal receiving chambers for receiving the terminal fittings, and a spacer 4 to be inserted into the connector housing through an opening. A receptacle for inserting an unlocking jig is formed on the spacer. The receptacle is opened at an outer wall of the spacer and a boundary wall to the connector housing 3. The receptacle is disposed in a manner not to spread across two terminal-receiving chambers. The receptacle communicates with one of the terminal-receiving chambers. A block of a main body of the spacer blocks a path between the receptacle and the other terminal-receiving chamber.