The present invention relates to an apparatus of manufacturing an aerogel sheet. The apparatus of manufacturing the aerogel sheet includes: a fixing vessel into which a blanket is inserted; and an impregnation device putting a silica sol precursor into the blanket inserted into the fixing vessel to impregnate and gelate the silica sol precursor, wherein the impregnation device includes a rotation roller moving from one end to the other end of a top surface of the blanket while rotating to put the stored silica sol precursor into the blanket and thereby to impregnate and gelate the silica sol precursor.