A guide carriage of a linear roller bearing, having at least one endless raceway for rolling bodies (9), and having a carrying body (1), on the two longitudinal sides of which in each case one carrying section (2, 3) and one return section (5, 6) of the endless raceway is provided, the carrying section (2, 3) being provided rolling bodies (9) which roll under load and the return section (5, 6) being provided for rolling bodies (9) which return without load, and having head pieces (13) which are arranged on end sides of the carrying body (1) and in each case have one deflection section (11, 12) which connects the return section (5, 6) to the carrying section (5, 6) a lubricant channel (24) being provided for the supply of lubricant, which lubricant channel (24) can be connected to the raceway of the rolling body (9) via a valve (30), the valve (30) having a slot (33) which is provide for the passage of lubricant, crosses the cross section of the lubricant channel (24) and is delimited by slot faces (34), the slot faces (34) bearing against one another when the valve (30) is shut, with the slot (33) being closed.