To prevent foam entering a groove of a trunk lid or a hood from being easy to remain by being influenced by wind, in a bubble spraying process spraying foam processing agent on a vehicle body surface in a car washing machine.

In a water sprinkling process after the foam spraying process, water is linearly dropped from a discharge port 23 of a water sprinkling pipe 22 of a water sprinkling device 15 to the whole of a vehicular width direction of a washed vehicle V.