Diffuser for a radial compressor, comprising: a diffusor duct portion which is formed by a first side wall and a second side wall, wherein the first side wall and the second side wall are arranged so as to diverge at least partially from one another in the direction of flow, a blade ring having a number of blades (6, 6'), wherein the blades (6, 6') are arranged at least partially in the diffusor duct portion, wherein each of the blades (6, 6') has a pressure side and a suction side, and wherein the pressure side and the suction side of each blade (6, 6') are delimited by a blade leading edge and by a blade trailing edge of said blade (6, 6'), a number of pressure equalizing openings (7, 7') which are incorporated in at least one of the two side walls (3, 4) of the diffuser duct portion, wherein each of the number of pressure equalizing openings (7, 7') is arranged between the pressure side of one blade and the suction side of the adjacent blade of the blade ring, a first annular duct, which is arranged behind the pressure equalizing openings (7, 7'), wherein the first annular duct is fluidically connected to the diffuser duct portion via at least two of the pressure equalizing openings (7, 7'), with the result that a number of diffuser passages of the diffuser are fluidically connectable together, wherein a region between two adjacent blades (6, 6') of the blade ring in the diffuser duct portion is denoted diffuser passage, and wherein the diffuser is characterized in that the number of pressure equalizing openings (7, 7') which are incorporated in at least one of the two side walls (3, 4) of the diffuser duct portion are arranged in a region of the respective side wall (3, 4) in which the first side wall and second side wall are arranged so as to diverge at least partially from one another in the direction of flow. a diffusor duct portion which is formed by a first side wall and a second side wall, wherein the first side wall and the second side wall are arranged so as to diverge at least partially from one another in the direction of flow, a blade ring having a number of blades (6, 6'), wherein the blades (6, 6') are arranged at least partially in the diffusor duct portion, wherein each of the blades (6, 6') has a pressure side and a suction side, and wherein the pressure side and the suction side of each blade (6, 6') are delimited by a blade leading edge and by a blade trailing edge of said blade (6, 6'), a number of pressure equalizing openings (7, 7') which are incorporated in at least one of the two side walls (3, 4) of the diffuser duct portion, wherein each of the number of pressure equalizing openings (7, 7') is arranged between the pressure side of one blade and the suction side of the adjacent blade of the blade ring, a first annular duct, which is arranged behind the pressure equalizing openings (7, 7'), wherein the first annular duct is fluidically connected to the diffuser duct portion via at least two of the pressure equalizing openings (7, 7'), with the result that a number of diffuser passages of the diffuser are fluidically connectable together, wherein a region between two adjacent blades (6, 6') of the blade ring in the diffuser duct portion is denoted diffuser passage, and wherein the diffuser is characterized in that the number of pressure equalizing openings (7, 7') which are incorporated in at least one of the two side walls (3, 4) of the diffuser duct portion are arranged in a region of the respective side wall (3, 4) in which the first side wall and second side wall are arranged so as to diverge at least partially from one another in the direction of flow.