A plugged honeycomb structure including particulate matter (PM) trapping layers disposed on the surfaces of the partition walls extending up to inflow side end faces of the plugging portions that plug outflow cells so that adjacent PM-trapping layers with the partition walls and the plugging portion therebetween are disposed so as to continue on the inflow side end faces of the plugging portions. The PM-trapping layers are extended up to the inflow side end faces of the plugging portions to form protruding portions having a protrusion height corresponding with 0.1 to 2 times the length of a side of the outflow cells from the inflow side end faces of the plugging portions toward the outside of the cell extension direction.