The neurophysiological mechanisms underlying retention of creative potential during aging are still poorly studied. Previously, we have identified age-related changes in the temporal dynamics of brain activity and the speed of creative problem solving at its initial stage, suggesting that younger and older subjects used different strategies. These differences in strategies may also be observed at the final stage of problem solving. Therefore, we have studied the pattern of temporal changes in the EEG spectral characteristics (event-related spectral perturbation, ERSP) in younger (N = 89, 22.1 ± 3.2 years) and older (N = 90, 64.9 ± 6.7 years) age cohorts during 600 ms before the preparation to motor response, which indicates that solution is found. The general and ageand sex-related features of the oscillatory brain activity at the final stage of problem solving were revealed. All subjects displayed statistically significant EEG temporal dynamics associated with a reduction of power reactivity of rhythms prior to the response. The age-related differences included more pronounced ERSP frontal–parietal gradient in the θ frequency range and lower ERSP values in the β frequency range in elderly subjects as compared with the younger individuals. The most pronounced age-related differences in the β1 rhythm were observed in the posterior cortex. The age-related differences in the α3 frequency range were mediated by the sex factor: lateral differences were pronounced only in young men, and the coefficient of hemispheric asymmetry in this group differed significantly from that in older men and younger women. These data reflect the changes in EEG that were associated with the evaluation of creative idea, making a decision about completion of the search, and intention to make a motor response that indicates that solution is found.