according to an aspect of the present invention , there is provided a handle unit including : a main body including : a pair of bearings ; and a pair of holding walls separated from the pair of the bearings ; a handle including : a pair of support walls ; and a pair of rotational shafts projecting outward from the pair of support walls to be engaged with the pair of the bearings , wherein the handle is rotatable between a stored position and a operating position , wherein the support walls are formed to not face the holding walls when the handle is in the stored position , and formed to face the holding walls and contact the holding walls by being deflected when the handle is in the operating position .