This paper describes the reasons why the lubricating ability of lapped surfaces is worse than that of scraped or milled surfaces, and method of improvement also is proposed. First, the permeability of the lubricant on the surfaces machined by some machining methods was measured using an optical flat. Next, oil grooves with 0.6 mm intervals on a lapped surface were produced by laser machining for improving the lubricating ability. Friction forces and rising values of a table from the guideway in each of sliding surfaces were measured using a prototype machine. As a result, the lapped surface improved by laser machining illustrated the possibility of a high-accuracy slider.