An alcohol sensor (204) outputs an electrical signal corresponding to the alcohol concentration. When an exposure mechanism (203) measures the alcohol concentration, the exposure mechanism (203) exposes the alcohol sensor (204) to the outside air. When the alcohol sensor (204) is exposed to the outside air, a CPU (205) calculates the alcohol concentration based on the electrical signal output by the alcohol sensor (204). The CPU (205) displays on a display a notification for replacement of the alcohol sensor when a total sum of a value corresponding to the duration that the alcohol sensor (204) has been exposed to the outside air exceeds a predetermined value.
