The present invention relates to a fuel jetting device which comprises: a barrel in which a plunger chamber is formed; a plunger movably installed along with a moving axis of the plunger chamber; and a first movable groove formed on an external surface of the plunger facing the barrel from the moving axis. The first movable groove is formed on the plunger to reduce the size of the first movable groove according as the first movable groove gets closer to the moving axis from an external surface of the plunger. According to the present invention, an eddy current in the first movable groove is prevented while a lubricant flows through the first movable groove to make the flow of the lubricant smooth.
