A lock part for locking an inserted state of a flexible printed circuit (FPC) is provided, in a housing of a connector, on both sides of an insertion portion in a width direction. Each of the lock parts has an arm portion and a projected portion formed on an inner side portion of the arm portion in the width direction and is protruded into the insertion portion. The arm portion has a cantilever shape with a stationary end and a free end and extends, in a depth direction, to the free end from an insertion side portion on an FPC insertion side, and can be elastically deflected outward in the width direction. The projected portion has tilted portions tilted relative to the depth direction toward the free end and the insertion side portion, and is detachably engaged with a notch on a side of the inserted FPC in the width direction.