To provide an on-vehicle structure of a battery pack hardly subjected to thermal influence from an adjacent position while the space up to a coil spring is effectively utilized.

In an on-vehicle structure of a battery pack 10, a vehicle includes a side member 115 and a cross member 116 for supporting the battery pack through a sub-frame 21, and the battery pack forms a storing space for battery module array BM inside an upper case 11 and a lower case as a liquid-tight closed space by a seal member 31 in a flange-shaped opening edge part 11a of the opening edge of the case. An adjacent part of an exhaust pipe 118 of the case (a space up to a coil spring 117) is formed as a tapered outer surface to secure a separation distance up to the seal member 31 in the opening edge part.