Abstract: In a connector that includes a slider having a cam groove which a boss of a mating connector is to enter and a lever making the slider perform an operation, sliders are positioned in a space between an inner housing and an outer housing, and a protrusion is formed on one of the sliders and the inner housing and a concave portion is formed on the other. In a separation state from the mating connector, the sliders are pushed by spring pieces to be in a locked state, in which the protrusion enters the concave portion, and accordingly, the sliding operation and the operation of a lever are both blocked. When fitting with the mating connector is started, the sliders are pushed by the mating connector, and accordingly, the sliders are displaced in directions separating from the inner housing, and the locked state is released.