A porous particle produced by a method comprising jetting a jetting liquid containing a material of which the porous particle is formed, a good solvent for the material of which the porous particle is formed, and a poor solvent for the material of which the porous particle is formed, to form the porous particle formed of the material of which the porous particle is formed, wherein the porous particle comprises an aliphatic polyester-based resin wherein the aliphatic polyester-based resin is polylactic acid-glycolic acid copolymer (PLGA), wherein the good solvent and the poor solvent are compatible with each other, wherein the molar ratio of good solvent: poor solvent is from 1:99 through 99:1, wherein the porous particle has a mass median aerodynamic diameter and a volume average particle diameter that satisfy the expression: y ≥ 2x, where x denotes the mass median aerodynamic diameter as measured by cascade impaction method using Andersen non-bubble sampler AN-200 (TOKYO DYLEC CORP.) and y denotes the volume average particle diameter as measured using a laser diffraction/scattering particle size distribution analyzer MICROTRAC MT3000II (MicrotracBEL Corp.), and the porous particle has a relative span factor (R.S.F) that satisfies the expression: 0 < (R.S.F) ≤ 1.5, wherein the (R.S.F) is defined as (D90-D10)/D50, in which D90 denotes cumulative 90% by volume, D50 denotes the cumulative 50% by volume, and D10 denotes the cumulative 10% by volume, from the small particle side of the cumulative particle size distribution, wherein the (R.S.F) is as measured by dynamic light scattering method using fiber-optics particle analyzer FPAR-1000 (Otsuka Electronics Co., Ltd.). jetting a jetting liquid containing a material of which the porous particle is formed, a good solvent for the material of which the porous particle is formed, and a poor solvent for the material of which the porous particle is formed, to form the porous particle formed of the material of which the porous particle is formed, wherein the porous particle comprises an aliphatic polyester-based resin wherein the aliphatic polyester-based resin is polylactic acid-glycolic acid copolymer (PLGA), wherein the good solvent and the poor solvent are compatible with each other, wherein the molar ratio of good solvent: poor solvent is from 1:99 through 99:1, wherein the porous particle has a mass median aerodynamic diameter and a volume average particle diameter that satisfy the expression: y ≥ 2x, where x denotes the mass median aerodynamic diameter as measured by cascade impaction method using Andersen non-bubble sampler AN-200 (TOKYO DYLEC CORP.) and y denotes the volume average particle diameter as measured using a laser diffraction/scattering particle size distribution analyzer MICROTRAC MT3000II (MicrotracBEL Corp.), and the porous particle has a relative span factor (R.S.F) that satisfies the expression: 0 < (R.S.F) ≤ 1.5, wherein the (R.S.F) is defined as (D90-D10)/D50, in which D90 denotes cumulative 90% by volume, D50 denotes the cumulative 50% by volume, and D10 denotes the cumulative 10% by volume, from the small particle side of the cumulative particle size distribution, wherein the (R.S.F) is as measured by dynamic light scattering method using fiber-optics particle analyzer FPAR-1000 (Otsuka Electronics Co., Ltd.). <EOS>