To provide a device and a method for improving a percentage of correctly separating trash and taking the trash out on a garbage collection day.

In the method, a radio-frequency IC tag is adhered to the trash 4. If the trash 4 approaches a trash-throwing port 1 of a trash collection box 3 etc., a radio-frequency IC tag reader-writer 2 senses it, accesses a trash article information database, recognizes the information of trash articles to determine whether the information corresponds to the collection day or not, makes a person who has thrown in the trash know by a sound or letters, etc., and registers the article information and the throw-in day to a trash takeout record database as needed.