Provided is a device for measuring blood alcohol concentration for detecting the alcohol concentration from the blood of the unconscious driver as well as the driver's breath. The device comprises a first body (60) including a coupling recess (82) into which the blood collection module (1) is coupled and a heater (83) for heating the coupled blood collection module (1), and a second body (90) including a detection probe (93) to penetrate the blood collection module (1) to suck the alcohol gas in the blood collection module (1), and an alcohol detection sensor (91) to detect the alcohol concentration through the alcohol gas introduced through the detection probe (93).