NOVELTY - A cutting fluid composition comprises cutting base (A), surfactant (B) chosen from anionic activator, cationic activator, and nonionic activator having clouding point of 65 degrees C or more, and water. The content of base (A) in the cutting fluid composition is 50-85 %mass. The base (A) contains ethyleneoxy group-containing compound (A1) (I) and propyleneoxy group-containing compound (A2) (II), and has clouding point of 30-65 degrees C. The cutting fluid composition has a viscosity of 1-25 mPa.second at 25 degrees C.    USE - Cutting fluid composition is used in manufacture of silicon wafer (claimed) used for manufacturing solar cells.    ADVANTAGE - The cutting fluid composition has excellent permeability, and enables manufacture of silicon wafer with efficient separation of drainage liquid and regeneration of cutting fluid composition.    DETAILED DESCRIPTION - A cutting fluid composition comprises cutting base (A), surfactant (B) chosen from anionic activator, cationic activator, and nonionic activator having clouding point of 65 degrees C or more, and water. The content of base (A) in the cutting fluid composition is 50-85 %mass. The base (A) contains ethyleneoxy group-containing compound (A1) of formula: R1-O-(CH2-CH2-O)p-H (I) and propyleneoxy group-containing compound (A2) of formula: R2-O-(CH2-CH(CH3)-O)q-H (II), and has clouding point of 30-65 degrees C. The cutting fluid composition has a viscosity of 1-25 mPa.second at 25 degrees C.    R1,R2=3-8C alkyl;    p=average addition mole number of ethyleneoxy group;    q=average addition mole number of propyleneoxy group;    p=3-6;and    q=1-6.    INDEPENDENT CLAIMS are included for the following:    (1) manufacture of silicon wafer, which involves cutting silicon ingot in a fixed abrasive wire saw using the cutting fluid composition, heating a drainage liquid containing the cutting fluid composition and a cutting powder of ingot at a temperature of 65 degrees C or more, separating the liquid into an upper layer containing cutting base as main component and a lower layer containing cutting powder and water as main components, removing lower layer from the drainage liquid after heating, adding water to the residual liquor, and regenerating the cutting fluid composition; and    (2) regeneration of cutting fluid composition.