A washing machine including a detergent case apparatus, the washing machine comprising: a washing machine body; a detergent case configured to be opened and closed, and having a groove or opening; a button on or in the washing machine body; and a case fixing apparatus configured to release the groove or opening and facilitate a movement of the detergent case by operation of the button, characterized in that the button includes: a button part having an end exposed outside the washing machine body; a moving part in the washing machine body and connected to the button part; and a guide in the washing machine body and configured to guide movement of the moving part, wherein the moving part includes: a support in the washing machine body and connected to the button part; one or more rails on one side or portion of the support, extending in a moving direction of the support, and abutting or contacting the guide; and a contact projection on another side or portion of the support and abutting or contacting the case fixing apparatus, and wherein the case fixing apparatus includes: a rotating shaft in the washing machine body; a rotating hook coupled with the rotating shaft and having one end configured to latch to or fit in the groove or opening; and a lever connected to another end of the rotating hook, configured to abut or contact the button and move the rotating hook into or away from the groove or opening. a washing machine body; a detergent case configured to be opened and closed, and having a groove or opening; a button on or in the washing machine body; and a case fixing apparatus configured to release the groove or opening and facilitate a movement of the detergent case by operation of the button, characterized in that the button includes: a button part having an end exposed outside the washing machine body; a moving part in the washing machine body and connected to the button part; and a guide in the washing machine body and configured to guide movement of the moving part, a button part having an end exposed outside the washing machine body; a moving part in the washing machine body and connected to the button part; and a guide in the washing machine body and configured to guide movement of the moving part, wherein the moving part includes: a support in the washing machine body and connected to the button part; one or more rails on one side or portion of the support, extending in a moving direction of the support, and abutting or contacting the guide; and a contact projection on another side or portion of the support and abutting or contacting the case fixing apparatus, and a support in the washing machine body and connected to the button part; one or more rails on one side or portion of the support, extending in a moving direction of the support, and abutting or contacting the guide; and a contact projection on another side or portion of the support and abutting or contacting the case fixing apparatus, and wherein the case fixing apparatus includes: a rotating shaft in the washing machine body; a rotating hook coupled with the rotating shaft and having one end configured to latch to or fit in the groove or opening; and a lever connected to another end of the rotating hook, configured to abut or contact the button and move the rotating hook into or away from the groove or opening. a rotating shaft in the washing machine body; a rotating hook coupled with the rotating shaft and having one end configured to latch to or fit in the groove or opening; and a lever connected to another end of the rotating hook, configured to abut or contact the button and move the rotating hook into or away from the groove or opening.