Washer

The present invention provides a technology capable of presenting information related to automatic input of a washing treatment agent to a user at an appropriate timing. A washer includes: a washing tub; an automatic feeding device for automatically feeding a washing treatment agent into the washing tub; a treatment agent tank which accommodates the washing treatment agent that is input into the washing tub by the automatic input device, and which is attached to and detached from the automatic input device; a detection unit for detecting the attachment/detachment of the treatment agent tank to/from the automatic feeding device and detecting the amount of the washing treatment agent contained in the treatment agent tank when the treatment agent tank is attached to the automatic feeding device; a display unit; and a control unit. When the detection unit detects that the treatment agent tank is attached to the automatic feeding device, the control unit displays, on the display unit, treatment dose information in