The scroll compressor includes stationary and moving volutes each including a scroll plate provided with a spiral wrap, the spiral wraps defining the variable-volume compression chambers, a delivery conduit including a first end emerging in a central compression chamber and a second end designed to be communicated with a delivery chamber, a delivery valve movable between closing and opening positions for closing and opening at least one delivery opening arranged to communicate the delivery conduit and the delivery chamber, at least one bypass valve associated with a bypass passage arranged to communicate the delivery chamber with an intermediate compression chamber. The compressor includes a retaining plate mounted on the scroll plate of the stationary scroll and on which first and second retaining elements are formed, the latter being arranged to limit respectively the amplitude of movement of the delivery valve and of each bypass valve toward the opening position thereof.