A refrigerator includes a main body, a storage room defined in the main body, and a cooling device configured to cool the storage room. The refrigerator also includes a door rotatably connected to the main body and configured to open and close the storage room. The refrigerator also includes a door storage mounted to the door and having a side storage portion that is accessible when the door is open to an acute opening angle. In addition, the refrigerator includes a door locking mechanism configured to selectively lock the door at the acute opening angle at which the side storage portion is exposed between the main body and the door.