A refrigerating and freezing device, comprising: a cabinet body, wherein at least one storage compartment is defined in the cabinet body, and a heating cavity configured to accommodate a to-be-processed object is defined in one of the storage compartments; and an electromagnetic heating device, configured to provide electromagnetic waves into the heating cavity to heat the to-be-processed object in the heating cavity, wherein the electromagnetic heating device is provided with an electromagnetic generation module configured to generate an electromagnetic wave signal and a power supply module configured to provide a power source to the electromagnetic generation module; wherein an accommodation groove with a backward opening is formed in a back of the cabinet body, the backward opening of the accommodation groove is covered with a cover body to define an accommodation space between the accommodation groove and the cover body, and heat dissipation holes configured to achieve communication between the accommodation space and an external environment where the cabinet body is located are formed in the cover body; and the power supply module is disposed in the accommodation space, and a heat dissipation fan is further disposed in the accommodation space and is configured to drive airflow to flow between the accommodation space and the external environment where the cabinet body is located through the heat dissipation holes, so as to dissipate heat from the power supply module, characterized in that the heat dissipation holes comprise an air inlet hole formed in a bottom of the cover body and an air outlet hole formed in a top of the cover body, so as to allow the airflow driven by the heat dissipation fan to enter the accommodation space through the air inlet hole and flow out through the air outlet hole, so as to carry out forced convection heat dissipation on the power supply module, wherein both the air inlet hole and the air outlet hole are covered with water retaining ribs, and bottoms of the water retaining ribs are spaced from a backward surface of the cover body, so as to allow the airflow to flow through. a cabinet body, wherein at least one storage compartment is defined in the cabinet body, and a heating cavity configured to accommodate a to-be-processed object is defined in one of the storage compartments; and an electromagnetic heating device, configured to provide electromagnetic waves into the heating cavity to heat the to-be-processed object in the heating cavity, wherein the electromagnetic heating device is provided with an electromagnetic generation module configured to generate an electromagnetic wave signal and a power supply module configured to provide a power source to the electromagnetic generation module; wherein an accommodation groove with a backward opening is formed in a back of the cabinet body, the backward opening of the accommodation groove is covered with a cover body to define an accommodation space between the accommodation groove and the cover body, and heat dissipation holes configured to achieve communication between the accommodation space and an external environment where the cabinet body is located are formed in the cover body; and the power supply module is disposed in the accommodation space, and a heat dissipation fan is further disposed in the accommodation space and is configured to drive airflow to flow between the accommodation space and the external environment where the cabinet body is located through the heat dissipation holes, so as to dissipate heat from the power supply module, characterized in that the heat dissipation holes comprise an air inlet hole formed in a bottom of the cover body and an air outlet hole formed in a top of the cover body, so as to allow the airflow driven by the heat dissipation fan to enter the accommodation space through the air inlet hole and flow out through the air outlet hole, so as to carry out forced convection heat dissipation on the power supply module, wherein both the air inlet hole and the air outlet hole are covered with water retaining ribs, and bottoms of the water retaining ribs are spaced from a backward surface of the cover body, so as to allow the airflow to flow through.