An apparatus for slip casting includes a pouring pipe for supplying slip, to which each mold is connected by way of a pouring hose having a pouring valve. A slip discharge pipe is provided in the vicinity of the pouring pipe. The pouring pipe and the slip discharge pipe are connected by a by-pass pipe which includes a rising pipe, a traverse pipe, a connecting pipe and an atmosphere pipe. Slip is fed from the pouring pipe to each mold. After a body is formed with a predetermined thickness in each mold 1, pressurized air is fed to the slip discharge spaces to discharge surplus slip to the slip discharge pipe. The height of the rising pipe is set so that the pressure of discharging the surplus slip and the head pressure of the slip within the rising pipe balance each other when the surplus slip is discharged to the slip discharge pipe. This allows the pressure within the slip discharge spaces to be stabilized.