A method for heat-treating a silicon single crystal wafer to control a BMD density thereof to achieve a predetermined BMD density by performing an RTA heat treatment on a silicon single crystal wafer composed of an Nv region in a nitriding atmosphere, and then performing a second heat treatment, the method including: formulating a relational equation for a relation between BMD density and RTA temperature in advance; and determining an RTA temperature for achieving the predetermined BMD density according to the relational equation. Consequently, a method for heat-treating a silicon single crystal wafer for manufacturing an annealed wafer or an epitaxial wafer each having defect-free surface and a predetermined BMD density in a bulk portion thereof.