To provide a control unit for an automobile capable of reducing the probability of improper wake up factor due to noise, and improving power-saving effect.

In an outside wake up signal which is made to be an edge effective signal, when level change is detected, if predetermined timing which is 1 or more after detection timing of the level change on the time series is used as post edge level detection timing, the level of an input signal at the post edge level detection timing is detected (post edge level detecting means 21). Only when change edge is detected and the level of the input signal detected by a post edge level detecting means 23 is a second level, a wake up command signal for waking up a main control portion 3 is outputted (a wake up command signal output means 22).