[en] The paper reports theoretical features of collimation and focusing of few-cycle optical beams in transparent isotropic dielectric medium. It was showed, that a spatial collimation of such short waves results in a peculiar shaping of spatio-temporal structure with the central part moving faster than its outlying areas and collimated beam loses with distance half cycle of temporal electromagnetic field oscillation. In focus of focusing mirror, number of oscillations in temporal field structure of beams depends on only temporal profile of radiation source, when focusing collimated wave packet. (paper)