The present invention relates to a casting apparatus for formation of a resin-made membrane, which comprises a temperature adjusting unit (a temperature sensor, a heating wire type heater and a temperature controller) whereby an inner wall surface temperature of a suction chamber can be set to a desired temperature. Thus, if a design is made to prevent the temperature of the inner wall surface of the suction chamber from dropping, no contamination of the inner wall of the suction chamber by a volatile matter occurs, so that it is possible to prevent the volatile matter from dropping onto a cooling roll to make a membrane dirty.