A flat conductor connector includes terminals, a housing, a slider movable between a retreat position and an advance position, and a detection member detecting the advance position. The housing includes a locking portion lockable to a flat conductor. The locking portion protrudes in an upper-lower direction. The slider allows at the retreat position, and restricts at the advance position, removal of the flat conductor. The slider includes an abutting portion and an arm portion. The abutting portion restricts movement of the flat conductor. The arm portion is lockable to the housing when the slider is at the advance position. The detection member attached to the slider moves around a detection position, and includes a restriction portion. The detection member at the detection position makes the restriction portion abuttable with the arm portion The detection member absent from the detection position prohibits the restriction portion from abutting the arm portion.