A flaskless molding machine includes: an upper sand tank storing the mold sand to be supplied to the upper molding space; a first lower sand tank storing the mold sand to be supplied to the lower molding space, and having a first communication port for discharging the stored mold sand; a second lower sand tank having a second communication port capable of communicating with the first communication port of the first lower sand tank, and storing the mold sand supplied from the first lower sand tank and to be supplied to the lower molding space; at least one first guide member extending in a vertical direction, and guiding the upper flask, the lower flask and the second lower sand tank in the vertical direction; and a second guide member extending in the vertical direction, and guiding the first lower sand tank in the vertical direction.