A movable member (36) is located at a malfunction preventing position and a pair of functional terminals (25) are shorted by a shorting terminal (50) unless two housings (10, 20) are properly connected, whereas the movable member (36) is moved to a connection detecting position and the shorting terminal (50) shorts a pair of detection terminals (14) at the same time as being disengaged from the pair of functional terminals (25) when the two housings (10, 20) are properly connected. Since the shorting terminal (50) is commonly used to short the pair of functional terminals (25) for the malfunction prevention and the like and to short the pair of detection terminals (14) for the detection of a connected state of the two housings (10, 20), the number of parts can be reduced.