To provide a ceramic honeycomb filter, hardly causing melting damage even if the filter is regenerated, hardly causing clogging with ash and reducing an increase in pressure loss, by suppressing the pressure loss when exhaust gas passes, while maintaining collection performance of PM.
A plurality of ceramic honeycomb structures are joined in an exhaust gas-flowing direction on its end surface, and mutual partition walls of at least a part of the plurality of ceramic honeycomb structures are deviatively joined on a cross section orthogonal to the exhaust gas-flowing direction, and in a joined upstream side cell, the cell opening area ratio A0=(A02/A01) being the ratio of the cell opening area A01 on the cross section vertical to the exhaust gas-flowing direction and the cell opening area A02 in which the cell opening area A01 of the cell is reduced by the partition wall of the joined downstream side ceramic honeycomb structure has the average value of 0.9 or less in an optional 5 cells×5 cells=25 cells, and roughness (a maximum height Rz) of a partition wall end surface and a partition wall surface of the downstream side ceramic honeycomb structure is 15 μm or more.
SOGA WATARU
KOMATSU JUNJI
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