Provided are: a coating material for channels with which the inner surface of a channel can be coated by a very simple operation and which has the excellent ability to inhibit a biosubstance from adhering； a channel device and a platelet-producing channel device which each include the coating material for channels on at least some of the inner surface of the channel； and production processes therefor. The coating material for channels comprises a copolymer which comprises repeating units each including an organic group represented by the following formula (a) and repeating units each including an organic group represented by the following formula (b). The channel device and the platelet-producing channel device each include the coating material for channels on at least some of the inner surface of the channel. The production processes are for producing the devices. (In the formulae, Ua1, Ua2, Ua3, Ub1, Ub2, Ub3, and An- are as described in the description and the claims.).本發明係提供一種可用極為簡便之操作塗佈在流路的內部表面，且具有優異之生物物質的附著抑制能之流路用塗佈劑、以及於流路之內部表面的至少一部分具有前述流路用塗佈劑之流路裝置、血小板產生流路裝置及其製造方法。本發明係包含共聚物之流路用塗佈劑、以及於流路之內部表面的至少一部分具有前述流路用塗佈劑之流路裝置、血小板產生流路裝置及其製造方法，該共聚物係包含：下述式(a)表示之有機基的重複單位、與下述式(b)表示之有機基的重複單位。(式中，Ua1、Ua2、Ua3、Ub1、Ub2、Ub3及An-係如本說明書及申請專利範圍所記載)。
