Fine magnesium oxide particle dispersion liquid and method for producing same

A fine magnesium oxide particle dispersion liquid which is obtained by dispersing fine magnesium oxide particles in an aprotic solvent, and which is characterized in that the D 50 in the particle size distribution as measured by a dynamic light scattering method is 200 nm or less and the content of coarse particles having an average particle diameter of 500 nm or more is less than 1%; and a method for producing this fine magnesium oxide particle dispersion liquid.