Each of detecting circuits 36a, 36d, 36f, and 36h detects a key signal such as a horizontal synchronization signal, a vertical synchronization signal, a capsule ID, a WB coefficient, and error information, i.e., a key signal superposed on RF signals received by an RF receiving unit 33. Each of determining units 36b, 36c, 36e, 36g, and 36i determines whether an image is valid or invalid based on the result of detection. A recording deciding unit 36k decides whether to record the image information in a storage unit 35 or not based on the result of determination. Thus, a receiving apparatus 3 can stop recording the image information received when a trouble occurs, thereby preventing defective images from mixing into the recorded image information, and preventing a recorded image size from becoming large, whereby necessary images can be recorded within a predetermined examination time.