An exhaust gas purification device disposed in an exhaust passage (3, 4) of an internal combustion engine and provided with a particulate filter capturing granular matter in an exhaust gas discharged from the internal combustion engine, wherein the particulate filter includes: a wall-flow part including an inlet-side cell that is open only at an end on an exhaust gas inflow side, an outlet-side cell that is adjacent to the inlet-side cell and that is open only at an end on an exhaust gas outflow side, and a porous wall that partitions the inlet-side cell from the outlet-side cell; and a straight-flow part including a through cell that penetrates the filter in an axial direction thereof and that is open at the end on the exhaust gas inflow side as well as the end on the exhaust gas outflow side, and wherein in a cross section of the filter orthogonal to the axial direction, an outer peripheral region and a center region of the cross section are respectively provided with a plurality of inlet-side cells (22A, 22B), outlet-side cells (24A, 24B), and through cells (32A, 32B), cross-sectional areas of each of the inlet-side cells and each of the outlet-side cells present in the outer peripheral region of the cross section are larger than cross-sectional areas of each of the inlet-side cells and each of the outlet-side cells present in the central region of the cross section, and a cross-sectional area of each of the through cells present in the outer peripheral region of the cross section is smaller than a cross-sectional area of each of the through cells present in the central region of the cross section, wherein a cross section of the filter orthogonal to the axial direction is approximately circular, and when the radius of this cross section is defined as R, the central region is defined as a region from the center of the cross section to at least 1/2R of the radius R, and the outer peripheral region is defined as a region from the outer edge of the cross section to at least 1/5R of the radius R. a wall-flow part including an inlet-side cell that is open only at an end on an exhaust gas inflow side, an outlet-side cell that is adjacent to the inlet-side cell and that is open only at an end on an exhaust gas outflow side, and a porous wall that partitions the inlet-side cell from the outlet-side cell; and a straight-flow part including a through cell that penetrates the filter in an axial direction thereof and that is open at the end on the exhaust gas inflow side as well as the end on the exhaust gas outflow side, and wherein in a cross section of the filter orthogonal to the axial direction, an outer peripheral region and a center region of the cross section are respectively provided with a plurality of inlet-side cells (22A, 22B), outlet-side cells (24A, 24B), and through cells (32A, 32B), cross-sectional areas of each of the inlet-side cells and each of the outlet-side cells present in the outer peripheral region of the cross section are larger than cross-sectional areas of each of the inlet-side cells and each of the outlet-side cells present in the central region of the cross section, and a cross-sectional area of each of the through cells present in the outer peripheral region of the cross section is smaller than a cross-sectional area of each of the through cells present in the central region of the cross section, wherein a cross section of the filter orthogonal to the axial direction is approximately circular, and when the radius of this cross section is defined as R, the central region is defined as a region from the center of the cross section to at least 1/2R of the radius R, and the outer peripheral region is defined as a region from the outer edge of the cross section to at least 1/5R of the radius R.