To provide an electronic device detecting battery temperature at a prescribed position, which can be assembled quickly and easily.

A flexible temperature sensor is connected to a printed board so that a temperature detection part of the temperature sensor extends from the end part of the printed board. The temperature sensor is pressed by a positioning member arranged on an outer case, and made located at a prescribed position of a battery case where the temperature is to be measured, that is, a temperature measuring position, or the temperature sensor is positioned by inserting it into a tubular insertion part arranged at the temperature measuring position on the battery case, and prevented from fall-off by pressing it by a fall-off prevention member.