A vehicle (1, 1A) comprising: a first battery pack disposed inside the vehicle and that includes a first battery module, a battery housing part housing the first battery module, and a first case housing the battery housing part and a device housing part on which a lid is disposed; a second battery pack that includes a second battery module and a second case housing the second battery module, wherein the second battery pack is disposed on a bottom surface of the vehicle located on an outer side of the vehicle, characterized in that an air exchange rate of the first case is higher than an air exchange rate of the second case; flanges (54,55) are formed at an opening edge of the battery housing part and at an opening edge on a lower side of the device housing part, so as to leave clearances between the battery housing part and the device housing part and between the flanges (54,55); a clearance is formed between the device housing part and the lid; the second case includes a bottom plate and a peripheral wall that is formed so as to stand upright from the bottom plate, the peripheral wall has a hole provided therein, and a waterproof and moisture-permeable film is provided in the hole; the first case is configured so that air inside the first case can be replaced with air outside the first case through the clearance between the battery housing part and the device housing part and the clearance between the device housing part and the lid; the second case is configured so that air inside the second case can be replaced with air outside the second case through the waterproof and moisture-permeable film; and the vehicle further comprises an engine and an exhaust pipe connected to the engine, wherein the exhaust pipe is provided on the bottom surface of the vehicle and disposed at a position adjacent to the second case. a first battery pack disposed inside the vehicle and that includes a first battery module, a battery housing part housing the first battery module, and a first case housing the battery housing part and a device housing part on which a lid is disposed; a second battery pack that includes a second battery module and a second case housing the second battery module, wherein the second battery pack is disposed on a bottom surface of the vehicle located on an outer side of the vehicle, characterized in that an air exchange rate of the first case is higher than an air exchange rate of the second case; flanges (54,55) are formed at an opening edge of the battery housing part and at an opening edge on a lower side of the device housing part, so as to leave clearances between the battery housing part and the device housing part and between the flanges (54,55); a clearance is formed between the device housing part and the lid; the second case includes a bottom plate and a peripheral wall that is formed so as to stand upright from the bottom plate, the peripheral wall has a hole provided therein, and a waterproof and moisture-permeable film is provided in the hole; the first case is configured so that air inside the first case can be replaced with air outside the first case through the clearance between the battery housing part and the device housing part and the clearance between the device housing part and the lid; the second case is configured so that air inside the second case can be replaced with air outside the second case through the waterproof and moisture-permeable film; and the vehicle further comprises an engine and an exhaust pipe connected to the engine, wherein the exhaust pipe is provided on the bottom surface of the vehicle and disposed at a position adjacent to the second case.