The scroll compressor includes stationary and moving scrolls each including a scroll plate provided with a spiral wrap, the spiral wraps defining the variable-volume compression chambers, a separating plate mounted on the scroll plate of the stationary scroll and defining with the latter a first intermediate volume, and a delivery chamber defined by the separating plate and the sealed casing. The compressor includes a bypass passage arranged to communicate the first intermediate volume with an intermediate compression chamber, a flow passage arranged to communicate the first intermediate volume with the delivery chamber, and a bypass valve associated with the flow passage, each bypass valve associated with a flow passage mounted on the surface of the separating plate turned toward the delivery chamber and movable between closing and opening positions for closing and opening the flow passage.