The invention is related to a washing apparatus for cleaning milking related equipment comprising a washing apparatus connectable to an automatic milking station (2) by interconnecting pipelines in such a way as to enable the washing apparatus to circulate a washing fluid through the milking related equipment of the automatic milking station (2). The washing apparatus (6, 7) comprise a circulation tank 6 and a separate pre-filling tank (7), whereby filling in advance and holding of the washing fluid to be used in a subsequent washing step is enabled. The washing apparatus (6, 7) further comprises connecting means for connection of the pre-filling tank (7) to the circulation tank (6). By means of the invention the time needed to complete a cleaning procedure is shortened essentially, and a cleaning procedure rendered more effective. The invention further relates to such method.