A honeycomb structure includes at least one honeycomb unit. The at least one honeycomb unit has a longitudinal direction and includes zeolite and an inorganic binder. A content of the zeolite per apparent unit volume of the at least one honeycomb unit is about 230 g/L or greater. The at least one honeycomb includes plural cell walls extending from one end face to another end face along the longitudinal direction to define plural cell walls. A porosity of substantially all pores in the cell walls is about 40% or less. A porosity of pores having diameters in a range of about 0.005 μm through about 0.02 μm in the cell walls is about 5% or greater. A porosity of pores having diameters in a range of about 0.05 μm through about 0.2 μm in the cell walls is about 17.5% or greater.