An explosive spark estimation system comprising: - a measuring system that is adapted to measure intensity-time-waveform of light, included in a spark occurred from an object to be tested, the light being within at least one specific wavelength band including a wavelength band in which a peak appears when the spark is explosive; and - a processing system that is adapted to obtain at least one of a wavelength spectrum of the light and the intensity-time-waveform of the light in the at least one specific wavelength band, and to determine whether the spark is explosive based on whether the peak has been detected in the wavelength spectrum of the light in the at least one specific wavelength band, based on an amount of deviation between the wavelength spectrum of the light in the at least one specific wavelength band and a reference wavelength spectrum of light, or based on the intensity-time-waveform of the light in the at least one specific wavelength band; wherein the at least one specific wavelength band comprises at least one of a first wavelength band within not less than 588 nm and not more than 591 nm, a second wavelength band within not less than 552 nm and not more than 555 nm, and a third wavelength band within not less than 619 nm and not more than 623 nm; wherein the processing system is adapted to determine whether the spark is explosive based on whether a peak has been detected in a wavelength spectrum of light in the at least one of the first wavelength band, the second wavelength band, and the third wavelength band, or based on the amount of the deviation between the reference wavelength spectrum of the light and the wavelength spectrum of the light in the at least one of the first wavelength band, the second wavelength band, and the third wavelength band. - a measuring system that is adapted to measure intensity-time-waveform of light, included in a spark occurred from an object to be tested, the light being within at least one specific wavelength band including a wavelength band in which a peak appears when the spark is explosive; and - a processing system that is adapted to obtain at least one of a wavelength spectrum of the light and the intensity-time-waveform of the light in the at least one specific wavelength band, and to determine whether the spark is explosive based on whether the peak has been detected in the wavelength spectrum of the light in the at least one specific wavelength band, based on an amount of deviation between the wavelength spectrum of the light in the at least one specific wavelength band and a reference wavelength spectrum of light, or based on the intensity-time-waveform of the light in the at least one specific wavelength band; wherein the at least one specific wavelength band comprises at least one of a first wavelength band within not less than 588 nm and not more than 591 nm, a second wavelength band within not less than 552 nm and not more than 555 nm, and a third wavelength band within not less than 619 nm and not more than 623 nm; wherein the processing system is adapted to determine whether the spark is explosive based on whether a peak has been detected in a wavelength spectrum of light in the at least one of the first wavelength band, the second wavelength band, and the third wavelength band, or based on the amount of the deviation between the reference wavelength spectrum of the light and the wavelength spectrum of the light in the at least one of the first wavelength band, the second wavelength band, and the third wavelength band. to determine whether the spark is explosive based on whether the peak has been detected in the wavelength spectrum of the light in the at least one specific wavelength band, based on an amount of deviation between the wavelength spectrum of the light in the at least one specific wavelength band and a reference wavelength spectrum of light, or based on the intensity-time-waveform of the light in the at least one specific wavelength band; wherein the at least one specific wavelength band comprises at least one of a first wavelength band within not less than 588 nm and not more than 591 nm, a second wavelength band within not less than 552 nm and not more than 555 nm, and a third wavelength band within not less than 619 nm and not more than 623 nm; wherein the processing system is adapted to determine whether the spark is explosive based on whether a peak has been detected in a wavelength spectrum of light in the at least one of the first wavelength band, the second wavelength band, and the third wavelength band, or based on the amount of the deviation between the reference wavelength spectrum of the light and the wavelength spectrum of the light in the at least one of the first wavelength band, the second wavelength band, and the third wavelength band.