An apparatus for cleaning substrates on a carrier, which has in the interior thereof a plurality of longitudinal passages, which run parallel to one another and are connected to the outside at the underside of the carrier via openings. There is provided a plurality of elongated pipes, which are arranged on a pipe holder and are connected in a fluid-conducting manner to a fluid supply. A centring template is provided, which encompasses the pipes and is displaceable in the longitudinal direction thereof between an attachment position in the end region of the pipes away from the pipe holder and a working position, which lies between the attachment position and the pipe holder. The centring template bears against the carrier, such that the pipes are then aligned exactly with the longitudinal passages.