Battery Pack, Electronic Device, and Vehicle

A battery pack includes a battery module including a plurality of secondary batteries and a module case having a first internal space in which the secondary batteries are received; and a pack housing having an intermediate housing forming a second internal space in which the module case is received. At least one guide rail is disposed on an inner surface of the intermediate housing, the guide rail protruding in an inward direction toward the battery module and extending in a vertical direction to guide the insertion of the module case in the vertical direction. At least one guide protrusion portion on an outer surface of a horizontal direction of the module case, the guide protrusion portion protruding in an outward direction and extending in the vertical direction to move in the vertical direction along the guide rail, and having at least one compression protrusion to press the guide rail.