An anti-vibration method of a band saw blade in a band saw machine, which is constructed to cut a workpiece by shifting an endless band saw blade running in a circulating manner to a cutting direction, the method comprising: providing a blade guide (22, 23) that movably guides the band saw blade, and mounting a pair of nozzles on the blade guide (22, 23), the blade guide (22, 23) being slidable with respect to the workpiece so as to move the nozzles to a position proximate a cut groove (Wa) of the workpiece and inject a jetted high-pressure liquid into the cut groove (Wa) at the proximate position; the method being characterized by: injecting the jetted high-pressure liquid in a range of 1 - 10 Mpa from the nozzles: toward each side face of a body of the band saw blade upon an entering-side where the band saw blade enters into the cut groove (Wa) of the workpiece formed by the band saw blade in a cutting process; toward the bottom of gullets, which are defined by spaces between adjacent sawteeth of the body of the band saw blade; and toward a nearby area of the body of the band saw blade; suppressing vibration of the band saw blade, wherein the jetted high-pressure liquid is injected within gaps between the side faces of the band saw blade and the cut faces of the workpiece and is introduced into the cut groove (Wa) of the workpiece during the cutting process, the jetted high-pressure liquid hitting the side faces of the band saw blade to provide a collision force that sandwiches the band saw blade so as to suppress vibration of the band saw blade; and wherein the nozzles are orientated in a plane that extends both in the cutting direction and in a direction perpendicular to the side faces of the band saw blade, and wherein entire outlet openings of the nozzles are positioned below a midpoint of a height of the band saw blade such that the jetted high-pressure liquid is concentrated at a lower end of the band saw blade, the height of the band saw blade being in a direction that is perpendicular to the plane in which the nozzles are oriented. toward each side face of a body of the band saw blade upon an entering-side where the band saw blade enters into the cut groove (Wa) of the workpiece formed by the band saw blade in a cutting process; toward the bottom of gullets, which are defined by spaces between adjacent sawteeth of the body of the band saw blade; and toward a nearby area of the body of the band saw blade; suppressing vibration of the band saw blade, wherein the jetted high-pressure liquid is injected within gaps between the side faces of the band saw blade and the cut faces of the workpiece and is introduced into the cut groove (Wa) of the workpiece during the cutting process, the jetted high-pressure liquid hitting the side faces of the band saw blade to provide a collision force that sandwiches the band saw blade so as to suppress vibration of the band saw blade; and wherein the nozzles are orientated in a plane that extends both in the cutting direction and in a direction perpendicular to the side faces of the band saw blade, and wherein entire outlet openings of the nozzles are positioned below a midpoint of a height of the band saw blade such that the jetted high-pressure liquid is concentrated at a lower end of the band saw blade, the height of the band saw blade being in a direction that is perpendicular to the plane in which the nozzles are oriented.