The “superfine” time structure of the Jovian S burst decameter emission has been investigated with the aim to clarify the noise nature of the given radiation. The Jovian Io-B noise storm taken for analysis in the paper has been observed on June 8, 1997, with an acousto-optical spectrograph designed at the Observatory Nancay, and incorporated into the giant Kharkov, Ukraine, UTR-2 radio telescope, operating from 10 to 25 MHz. The presence of the flicker noise component in the processed signals has been shown with an application of the wavelet transform and maximum likelihood techniques. The spectral parameters γ characterizing such processes have been calculated for different frequencies and different time intervals. The set of randomly distributed pulses has been considered as one of the possible models of S bursts adiation, capable for producing this noise process.