Method of manufacturing silicon single crystal

[Subject] To provide a method of manufacturing a silicon single crystal, capable of suppressing generation of dislocation extending from a neck portion to a straight part of ingot. [Solving Means] A method of manufacturing a silicon single crystal according to this invention includes the steps of preparing a silicon melt (a preparation step (S10)), forming a neck portion continuing from a seed crystal by bringing the seed crystal in contact with the silicon melt (a neck portion formation step (S20)), separating the neck portion from the silicon melt (a separation step (S30)), decreasing a temperature of the neck portion separated from the silicon melt from a temperature of the neck portion in the neck portion formation step (S20) (a cooling step (S40)), and forming a silicon single crystal continuing from the neck portion by again bringing the neck portion in contact with the silicon melt after the cooling step (S40) (a re-growth step (S50)).