The article present the hypothesis that weak electromagnetic fields of ultra-low frequencies (0.5–26 Hz) could affect daytime sleep features and structure. Parameters of daytime sleep continuity were compared in the study with counterbalanced control/exposition (50 min exposure to electromagnetic field at 2 and 8 Hz / 0.004 μT) scheme in 14 healthy volunteers (8 men, 6 women, mean age 19.43 ± 1.22 y.o.). Nonlinear regression model was used to assess daytime sleep continuity. Exposure to a weak electromagnetic field of ultra-low frequency significantly improved the quality of sleep, assessed by the indicator of sleep continuity, namely, there were fewer transitions from the second and deeper stages of sleep to the first stage and to the state of wakefulness. The results can be used to develop non-pharmacological methods of sleep correction, as well as to improve the quality of short-term sleep and its positive effect on wellbeing, cognitive function and working capacity.