A method for slicing an ingot, including: forming a wire row by a wire spirally wound between a plurality of wire guides and configured to travel in an axial direction; and pressing an ingot against the wire row while supplying a contact portion between the ingot and the wire with a slurry from a nozzle, thereby slicing the ingot into wafers. The slurry is supplied such that slurries whose temperatures are separately controlled by two or more lines of heat exchangers are respectively supplied from two or more sections of the nozzle which are orthogonal to a travelling direction of the wire row. Consequently, a wire saw and a method for slicing an ingot are provided which enable separate control of wafer shapes depending on ingot-slicing positions.