An obstacle discrimination device has a first detection unit, a second detection unit which is more resistant to damage than the first detection unit, and an obstacle discrimination ECU. The obstacle discrimination ECU performs at least one of a discrimination for determining whether or not an obstacle colliding with a vehicle is a lightweight obstacle and a discrimination for determining whether or not the obstacle is a heavyweight obstacle based on detection signals of the first detection unit, and performs a discrimination for determining whether or not the obstacle is the heavyweight obstacle based on detection signals of the second detection unit. The obstacle discrimination ECU sends instructions corresponding to discrimination results to a pedestrian protection device and the like of the vehicle.