A double lock connector 1 having spacers 3,4 for engaging terminals is provided with detecting pin inserting portions 16,17 continuing from the front end of a connector housing 2 to the spacers 3,4. The detecting pin inserting portions are of slits. The detecting pin inserting portions 16,17 communicate with respective accommodating recesses 13,14 for base plate portions 9,10 of the spacers 3,4. Detecting pins are arranged opposite to the front end of the connector housing 2, and the detecting pins are inserted into the detecting pin inserting portions and abut against the respective spacers 3,4. The detecting pins are set inside a continuity testing portion of a terminal continuity testing member, and the continuity testing portion is moved toward the front end of the double lock connector 1. Thus, the presence of the spacers is securely detected.