A device treats substrates with a liquid, which device has a conveying device by which the substrates can be conveyed in a conveying direction through a container containing a liquid. A weir has an edge over which the substrates can run and which, at least in sections, extends obliquely relative to the conveying direction of the substrates. The weir is used in the device for treating substrates with a liquid. The weir has at least one edge which extends obliquely at least in sections.