Provided is a holder of a cutting insert that performs turning on a work by feeding a cutting edge in a Y axis direction which is different from a longitudinal direction (X axis) of a tool holder installed in a tool rest, and that can easily adjust the projection amount without contacting a part of the holder to the tool rest. A Y axis holder holds the cutting insert including a cutting edge to perform turning on a work that moves along the Z axis, and is installed in a state where relative movement in the X axis direction with respect to the tool rest is possible, such that a projection amount of the cutting insert along the X axis is changeable. The Y axis holder performs turning on the work using the cutting insert when the holder moves in the Y axis direction which is different from the X axis direction. The Y axis holder has a shape in which an end portion thereof in the X axis direction is projected from the cutting edge of the cutting insert, and a positioning portion to determine the projection amount of the cutting insert from the tool rest is disposed on the end portion.