It is aimed to prevent the damage and deformation of a terminal fitting. A connector is provided with a housing including a terminal accommodation chamber, and a terminal fitting including a tube portion and a resilient contact piece accommodated in the tube portion, the terminal fitting being inserted into the terminal accommodation chamber. A front wall portion of the housing is formed with a tab insertion hole into which a tab (T) of a mating terminal is inserted to enter the tube portion from front and contact the resilient contact piece. A left front plate portion is formed forward of the resilient contact piece in the terminal fitting. The front wall portion of the housing is formed with a detection hole open separately from the tab insertion hole. The detection hole is disposed at a position facing the left front plate portion in the front wall portion.