A flaskless molding machine forming a flaskless upper mold and lower mold, comprising: an upper flask; a lower flask disposed below the upper flask and capable of clamping a match plate with the upper flask; an upper sand tank disposed above the upper flask, communicating with a compressed air source, being open at a lower end thereof, and internally storing mold sand; an upper plate attached to a lower end of the upper sand tank, with at least one supply port being formed in the upper plate, the supply port allowing the upper sand tank to communicate with an inside of the upper flask; a first lower sand tank communicating with a compressed air source, internally storing mold sand, and having a first communication port for discharging the stored mold sand; a second lower sand tank disposed below the lower flask, being open at an upper end thereof, 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 into the lower flask; a lower plate attached to an upper end of the second lower sand tank, with at least one supply port being formed in the lower plate, the supply port allowing the second lower sand tank to communicate with an inside of the lower flask; and a drive unit configured to move the second lower sand tank in a vertical direction, and allowing the upper plate and the lower plate to perform squeezing; characterized by an adjustment drive unit configured to move the first lower sand tank in the vertical direction; a first detector configured to detect a height position of the first lower sand tank; a second detector configured to detect a height position of the second lower sand tank; and a control unit configured to operate the drive unit and the adjustment drive unit so that the height positions of the first communication port and the second communication port coincide with each other, based on detection results of the first detector and the second detector. an upper flask; a lower flask disposed below the upper flask and capable of clamping a match plate with the upper flask; an upper sand tank disposed above the upper flask, communicating with a compressed air source, being open at a lower end thereof, and internally storing mold sand; an upper plate attached to a lower end of the upper sand tank, with at least one supply port being formed in the upper plate, the supply port allowing the upper sand tank to communicate with an inside of the upper flask; a first lower sand tank communicating with a compressed air source, internally storing mold sand, and having a first communication port for discharging the stored mold sand; a second lower sand tank disposed below the lower flask, being open at an upper end thereof, 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 into the lower flask; a lower plate attached to an upper end of the second lower sand tank, with at least one supply port being formed in the lower plate, the supply port allowing the second lower sand tank to communicate with an inside of the lower flask; and a drive unit configured to move the second lower sand tank in a vertical direction, and allowing the upper plate and the lower plate to perform squeezing; characterized by an adjustment drive unit configured to move the first lower sand tank in the vertical direction; a first detector configured to detect a height position of the first lower sand tank; a second detector configured to detect a height position of the second lower sand tank; and a control unit configured to operate the drive unit and the adjustment drive unit so that the height positions of the first communication port and the second communication port coincide with each other, based on detection results of the first detector and the second detector.