A method of producing silicon blocks by cutting a silicon ingot is provided. The method uses a silicon ingot cutting slurry containing abrasive grains and an alkaline substance so as to provide the silicon blocks that can be produced into silicon wafers each having a thin thickness with reduced substrate damage at the time of producing a solar battery. The alkaline substance has a content mass that is at least 3.5% with respect to the mass of the entire liquid components of said slurry, and the slurry contains an organic amine having a mass ratio of 0.5 to 5.0 with respect to water in the liquid components of the slurry. The slurry is used at a pH of 12 or more and at a temperature of from 65 to 95 degrees C.