A particulate nucleating agent comprising: a compound represented by the following General Formula, wherein a range WA of a particle size distribution measured by the following procedure A and a range WB of a particle size distribution measured by the following procedure B satisfy the following Expression: 0.3 ≤ WA / WB ≤ 13.5 (Procedure A) Dispersion air of a dispersion pressure of 30 psi is blown to the particulate nucleating agent, and dry type measurement is performed on the particle size distribution of the particulate nucleating agent, setting the particulate nucleating agent dispersed in air as a measurement target, using a laser diffraction particle size measurement device. As the particle size distribution, a volume mean particle size MvA and a number mean particle size MnA of the particulate nucleating agent are obtained. Based on WA = MvA/MnA, the range WA of the particle size distribution is calculated. (Procedure B) Packed treatment is performed on the particulate nucleating agent set as the measurement target of the procedure A in the following manner: Packed treatment: the particulate nucleating agent is put in a tray made of an aluminum foil, and in a state in which a load of 60 g/cm 2 is added to the particulate nucleating agent in the tray, the tray is left still in a constant-temperature oven having a relative humidity of 80% at 40°C for 24 hours. Subsequently, without blowing dispersion air to the particulate nucleating agent, dry type measurement is performed on the particle size distribution of the particulate nucleating agent, setting the particulate nucleating agent after packed treatment dispersed in the air as the measurement target, using the laser diffraction particle size measurement device. As the particle size distribution, a volume mean particle size MvB and a number mean particle size MnB of the particulate nucleating agent are obtained. Based on WB = MvB/MnB, the range WB of the particle size distribution is calculated. (in the above General Formula, R 1 to R 4 each independently represent a hydrogen atom and a straight chain or branched alkyl group having 1 to 9 carbon atoms, R 5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, m represents 1 or 2, in a case where m is 1, M 1 represents a hydrogen atom or an alkali metal atom, and in a case where m is 2, M 1 represents a group 2 element, Al or Zn.) a compound represented by the following General Formula, wherein a range WA of a particle size distribution measured by the following procedure A and a range WB of a particle size distribution measured by the following procedure B satisfy the following Expression: 0.3 ≤ WA / WB ≤ 13.5 (Procedure A) Dispersion air of a dispersion pressure of 30 psi is blown to the particulate nucleating agent, and dry type measurement is performed on the particle size distribution of the particulate nucleating agent, setting the particulate nucleating agent dispersed in air as a measurement target, using a laser diffraction particle size measurement device. As the particle size distribution, a volume mean particle size MvA and a number mean particle size MnA of the particulate nucleating agent are obtained. Based on WA = MvA/MnA, the range WA of the particle size distribution is calculated. (Procedure B) Packed treatment is performed on the particulate nucleating agent set as the measurement target of the procedure A in the following manner: Packed treatment: the particulate nucleating agent is put in a tray made of an aluminum foil, and in a state in which a load of 60 g/cm 2 is added to the particulate nucleating agent in the tray, the tray is left still in a constant-temperature oven having a relative humidity of 80% at 40°C for 24 hours. Subsequently, without blowing dispersion air to the particulate nucleating agent, dry type measurement is performed on the particle size distribution of the particulate nucleating agent, setting the particulate nucleating agent after packed treatment dispersed in the air as the measurement target, using the laser diffraction particle size measurement device. As the particle size distribution, a volume mean particle size MvB and a number mean particle size MnB of the particulate nucleating agent are obtained. Based on WB = MvB/MnB, the range WB of the particle size distribution is calculated. (in the above General Formula, R 1 to R 4 each independently represent a hydrogen atom and a straight chain or branched alkyl group having 1 to 9 carbon atoms, R 5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, m represents 1 or 2, in a case where m is 1, M 1 represents a hydrogen atom or an alkali metal atom, and in a case where m is 2, M 1 represents a group 2 element, Al or Zn.) Packed treatment: the particulate nucleating agent is put in a tray made of an aluminum foil, and in a state in which a load of 60 g/cm 2 is added to the particulate nucleating agent in the tray, the tray is left still in a constant-temperature oven having a relative humidity of 80% at 40°C for 24 hours. Subsequently, without blowing dispersion air to the particulate nucleating agent, dry type measurement is performed on the particle size distribution of the particulate nucleating agent, setting the particulate nucleating agent after packed treatment dispersed in the air as the measurement target, using the laser diffraction particle size measurement device. As the particle size distribution, a volume mean particle size MvB and a number mean particle size MnB of the particulate nucleating agent are obtained. Based on WB = MvB/MnB, the range WB of the particle size distribution is calculated.