To provide a vice of work floating-up prevention structure type which is used when set on a machining tool so as to hold and fix a work (material).

This vice is provided with a fixed part having a fixed side base 2 at one side on a reference surface and a movable part having a movable side base 4 at the other end, wherein mutual contact surfaces of the fixed side base 2 and the fixed part and mutual contact surfaces of the movable side base 4 and movable part are formed so that both mutual contact surfaces thereof become slant surfaces showing the shapes of a pair of eyeblows whose outer ends declining in a side view, supporting is made such that the inclining contact surfaces of the fixed side base 2 and the movable side base 4 can slide reciprocally along the inclining contact surfaces of the fixed side part and the movable side part, and returning springs to return the bases 2, 4 upward are provided to them.