Stop assist device

A stop assist device comprising:

• an operation switch that is operated to activate a hazard lamp of a vehicle and deactivate the hazard lamp;
• and
• a control unit configured to determine whether or not an abnormality condition that is fulfilled when a driver of the vehicle falls into an abnormal state in which the driver is unable to drive the vehicle is fulfilled, and start stop assist control for stopping the vehicle through automatic deceleration of the vehicle and start activating the hazard lamp upon arrival of an abnormality detection timing when it is determined that the abnormality condition is fulfilled, wherein
• the control unit is configured to continue to perform the stop assist control when the operation switch is operated before lapse of a predetermined invalid time from the abnormality detection timing during performance of the stop assist control, and end the stop assist control when the operation switch is operated after lapse of the invalid time from the abnormality detection timing during performance of the stop assist control.