A particulate filter for exhaust-gas aftertreatment in an internal combustion engine has a housing on which an inlet and an outlet are configured on opposite ends. The particulate filter also has a filter element arranged in the housing, said filter element having essentially parallel filter channels that are each alternatingly closed on the inlet side or on the outlet side by a closure in order to prevent gas from passing directly through the filter element. In this context, the filter channels can be divided into a first group of filter channels which are closed on the outlet side by a closure, and into a second group of filter channels which are closed on the inlet side by a gas-tight closure. The filter channels of the second group are additionally closed on the outlet side by a high-porosity closure in order to improve the cleaning effect of the particulate filter.

An exhaust gas purification filter collects PM contained in and purifies exhaust gas emitted from a gasoline direct injection engine. The exhaust gas purification filter has a honeycomb structural body which has a plurality of cells, partition walls and plug members. Each of the cells is surrounded by the partition walls. An opening section of one end of each of the cells is plugged by a plug member. The plug members satisfies a relationship of L/D50 and L3, where L is an average length (mm) of the plug members and D is an average pore size mm of the plug members. The honeycomb structural body and the plug members are made of cordierite. The cordierite contains silica, talc, kaolin, alumina and/or aluminum hydroxide, etc.

A honeycomb filter includes a honeycomb structure having a porous partition wall and a plurality of plugging portions, wherein a porosity of the plugging portion is 40 to 60%, a central plugging portion having a plugging length of 5 mm or more and an outer peripheral plugging portion having the plugging length of less than 5 mm are disposed, an average plugging length L1.sub.(Ave) is 5 mm or more and 10 mm or less, an average plugging length L2.sub.(Ave) is 2 mm or more and less than 5 mm, a difference between L1.sub.(Ave) and L2.sub.(Ave) is 2 to 6 mm, a ratio of an average radius of the center part to an equivalent circle diameter of the end face is 0.2 to 0.5, the plugging portion is composed of a plurality of particles, an average value of an equivalent circle diameter of each particle is 3 to 5 ?m, and a particle density is 750 to 1250 particles/mm.sup.2.

The honeycomb structure includes a honeycomb structure part having porous partition walls, and porous plugged portions, and when there is drawn a straight line as an inner boundary line which is positioned at a distance of 30% of a distance between an outer end surface and an inner end surface, from the inner end surface, and there is drawn a straight line as an outer boundary line which is positioned at a distance of 70% of the distance between the outer end surface and the inner end surface, from the inner end surface, each of the plugged portions has an outer region, and an inner region which is the region between the inner end surface and the inner boundary line and whose porosity is larger than a porosity of the outer region.

A honeycomb filter comprising a pillar-shaped honeycomb structure having a porous partition wall disposed so as to surround a plurality of cells which serve as a fluid through channel extending from an inflow end face to an outflow end face and a porous plugging portion provided at either an end on the inflow end face side or an end on the outflow end face side of the cell, wherein in a processed image obtained by binarizing an electron microscope image of a visual field area of 480 m640 m of the plugging portion, the plugging portion is composed of a plurality of particles, and the number of the particles having an area of 0.25 m.sup.2 or more is 1000 or more and 3500 or less.

A honeycomb filter includes a honeycomb structure having a porous partition wall and a plurality of plugging portions, wherein a porosity of the plugging portion is 40 to 60%, a central plugging portion having a plugging length of 5 mm or more and an outer peripheral plugging portion having the plugging length of less than 5 mm are disposed, an average plugging length L1.sub.(Ave) is 5 mm or more and 10 mm or less, an average plugging length L2.sub.(Ave) is 2 mm or more and less than 5 mm, a difference between L1.sub.(Ave) and L2.sub.(Ave) is 2 to 6 mm, a ratio of an average radius of the center part to an equivalent circle radius of the end face is 0.2 to 0.5, the plugging portion is composed of a plurality of particles, an average value of an equivalent circle diameter of each particle is 3 to 5 m, and a particle density is 750 to 1250 particles/mm.sup.2.