A linear compressor comprising: a shell including an intake pipe configured to receive a refrigerant therein; a cylinder provided inside the shell ; a piston configured to reciprocate in an axial direction inside the cylinder , the piston including a piston body ; and an intake muffler including a first muffler , wherein the first muffler includes a first muffler body disposed inside the piston body and a first muffler flange extending in a radial direction from the first muffler body ; wherein the first muffler body defines a main flow passage (PA1) having an inlet hole for receiving the refrigerant into the main flow passage (PA1); and wherein the linear compressor further comprises: at least one auxiliary flow passage (PA2, PA2-1, PA2-2) disposed between an outer peripheral surface of the first muffler body and an inner peripheral surface of the piston body and fluidly connecting a space between the first muffler body and the piston body to an outside of the piston and/or to an inside of the intake muffler ; characterized in that a cross-sectional area of the auxiliary flow passage (PA2, PA2-1, PA2-2) is less than a cross-sectional area of the inlet hole of the main flow passage (PA1), wherein the cross-sectional area of the auxiliary flow passage (PA2, PA2-1, PA2-2) is greater than or equal to 10 % of the cross-sectional area of the inlet hole of the main flow passage (PA1). a shell including an intake pipe configured to receive a refrigerant therein; a cylinder provided inside the shell ; a piston configured to reciprocate in an axial direction inside the cylinder , the piston including a piston body ; and an intake muffler including a first muffler , wherein the first muffler includes a first muffler body disposed inside the piston body and a first muffler flange extending in a radial direction from the first muffler body ; wherein the first muffler body defines a main flow passage (PA1) having an inlet hole for receiving the refrigerant into the main flow passage (PA1); and wherein the linear compressor further comprises: at least one auxiliary flow passage (PA2, PA2-1, PA2-2) disposed between an outer peripheral surface of the first muffler body and an inner peripheral surface of the piston body and fluidly connecting a space between the first muffler body and the piston body to an outside of the piston and/or to an inside of the intake muffler ; characterized in that a cross-sectional area of the auxiliary flow passage (PA2, PA2-1, PA2-2) is less than a cross-sectional area of the inlet hole of the main flow passage (PA1), wherein the cross-sectional area of the auxiliary flow passage (PA2, PA2-1, PA2-2) is greater than or equal to 10 % of the cross-sectional area of the inlet hole of the main flow passage (PA1). at least one auxiliary flow passage (PA2, PA2-1, PA2-2) disposed between an outer peripheral surface of the first muffler body and an inner peripheral surface of the piston body and fluidly connecting a space between the first muffler body and the piston body to an outside of the piston and/or to an inside of the intake muffler ; characterized in that a cross-sectional area of the auxiliary flow passage (PA2, PA2-1, PA2-2) is less than a cross-sectional area of the inlet hole of the main flow passage (PA1), wherein the cross-sectional area of the auxiliary flow passage (PA2, PA2-1, PA2-2) is greater than or equal to 10 % of the cross-sectional area of the inlet hole of the main flow passage (PA1). <EOS>