A thrust reverser for a turbojet engine nacelle includes a movable cowl, cascade vanes and a portion forming a movable variable nozzle. The cowl translates between a closing position and a maintenance position which is located beyond a thrust reversal position. In the maintenance position, the cowl opens a passage within the nacelle and allows access the inside of the nacelle. The variable nozzle is translated by an actuator between reduced ejection section and increased section positions. In particular, the cascade vanes move between retracted and active positions and are housed in an envelope formed by a fan casing and an outer cowl in the retracted position. In the active position, the cascade vanes are displaced downstream by an actuator through a passage open by the movable cowl in the nacelle. The actuator of the cascade vanes is dissociable from the actuator driving the variable nozzle.