An apparatus for manufacturing a hydrogel using a mask film is presented, in which the apparatus has a constant osmotic pressure, generates a large amount of diluent in a short time, and stabilizes the rigidity and structure of the hydrogel, thereby increasing a skin care effect by means of a mask pack. The apparatus comprises: a hydrosol supply device which is disposed in a space provided by first and second supply rollers and supplies a hydrosol to a support film to form a first coating layer; a pressing roller into which the support film, the first coating layer, and a mask film are input to allow a portion of the first coating layer to protrude by the pressure provided by the pressing roller, and thus an uneven coating layer having irregularities is provided; and an essence sprayer which sprays an essence composed of an active material and moisture onto the support film, the uneven coating layer and the mask film.