Disclosed is a linear compressor. The linear compressor according to the spirit of the present invention includes a cylinder forming a compression space for refrigerant and a discharge unit forming a discharge space for refrigerant into which refrigerant discharged from the compression space flows. The discharge unit includes a discharge cover having an inner space formed therein and a discharge plenum placed in the inner space. In this case, the discharge plenum includes a plenum flange extending radially, a plenum seating part, a plenum body, and a plenum extension part which extend from a radially inner side end of the plenum flange, and a plenum guide surface extending from a radially outer side end of the plenum flange toward the inner space.