A filter unit has a filter chamber disposed in a channel through which liquid is to be supplied to a liquid discharge unit. The filter unit has a filter and a partition. The filter is disposed in the filter chamber, inclined relative to a horizontal direction. The filter separates the filter chamber into an upstream chamber the liquid to be supplied and a downstream chamber in communication with the liquid discharge unit. The partition has a wall surface facing the filter. The partition separates the upstream chamber into a first chamber the liquid to be supplied to and a second chamber adjacent to the filter. The filter unit has, in an upper portion of the partition, an opening that allows communication between the first chamber and the second chamber.