To provide a microwave heating garbage disposer which can dry garbage properly irrespective of the kind of the garbage without causing ignition and burning by heating garbage excessively.

The garbage disposer in which a garbage is put in a treatment container, agitated while being supplied with air, heated and dried by being irradiated with microwaves from a magnetron while being shredded by a rotary cutter has a temperature sensor for detecting the temperature of exhaust gas from the treatment container and a humidity sensor for detecting the humidity of the exhaust gas from the treatment container. The detected temperature by the temperature sensor and the detected humidity by the humidity sensor are monitored. When the detected temperature is increased sharply from a mild linear upward transition, or when the detected humidity is decreased sharply from a mild linear downward transition, drying by the magnetron is finished automatically.