Exhaust gas purification filter

An exhaust gas purification filter comprising:

• a plurality of cells each disposed to extend in an axial direction (X) of the filter, each of the cells having opposing first and second ends in the axial direction;
• a partition wall configured to have a porous structure and define the plurality of cells partitioned from each other;
• and
• a plurality of seal members disposed alternately in the first and second ends of the respective cells, each of the seal members being configured to seal a corresponding one of the first end and the second end of a corresponding one of the cells, wherein:
• the partition wall has a gas-inflow-side surface, a gas-outflow-side surface, and communicating pores, each of the communicating pores being formed through the partitioning wall to open on each of the gas-inflow-side surface and gas-outflow-side surface,
• each of the communicating pores has, as viewed in cross section in a thickness direction of the partition wall, a surface opening on the gas-inflow-side surface and a plurality of portions,
• each of the portions of each of the communicating pores having a diameter, the diameter of each of the portions of each of the communicating pores being reduced and then increased again from the surface opening of the corresponding one of the communicating pores, one of the portions of each of the communication pores, whose diameter is the smallest, being defined as an inlet neck portion of the corresponding one of the communication pores,
• the surface opening of each of the communication pores has a diameter defined as a surface opening diameter,
• the inlet neck portion of each of the communication pores has a diameter defined as an inlet neck diameter,
• the inlet neck diameter of each of the communication pores is smaller than the surface opening diameter thereof, and
• an average value of the inlet neck diameters of the communication pores is 15 μm or less;
• and
• a surface opening ratio of the communicating pores in plan view of the gas-inflow-side partition wall surface is 40% or more.