An electronic device for a vehicle includes: a digital substrate having a first semiconductor package with a CPU, a second semiconductor package with a volatile memory readable and writable from the CPU, a third semiconductor package with a flash memory storing a start-up program of the CPU, and a fourth semiconductor package with a power supply management integrated circuit; and a fan that takes in air along the surface of the digital substrate on which the first to fourth semiconductor packages are mounted. The third semiconductor package is disposed to distance from the first semiconductor package by at least a first predetermined distance and to distance from the fourth semiconductor package by at least a second predetermined distance exceeding the first predetermined distance, and is disposed in a passage of the air taken in by the fan.