To provide a line marker for correctly and nicely drawing a line along a string without allowing lime to fall onto the string when the line is drawn by following the previously stretched string.

A guide is formed by bending a wire material which includes a grip part 4 formed by outward bending; center parts 5 inserted to metallic fixtures 3 so as to be freely vertically moved; a horizontal stem 6 disposed in the lower part of the center parts 5; and open legs 7 having a downward U shape in the lower part of the horizontal stem. The guide is attached to the metallic fixtures 3 on the front surface of a main body. Each center part 5 to be inserted to the metallic fixtures 3 so as to be freely vertically movable has a bending part which is bent inward by substantially maximally half size thickness of a wire trunk.