Investigations of the conditions for low losses in ultra-thin grain-oriented silicon steel sheets are described. The eddy current loss was found to be very large when the angle of inclination of the [001] axis against the sheet surface was 3?? or less. The effect of scribe processes on 0.1 mm sheets was studied, by performing scribing on 3 percent Si-Fe single-layer sheets while varying the scribe load and spacing. Saturation of loss reduction was thought to occur for a load of 90 g at a spacing of 2.5 mm or less. Scribing had an effect when large spacings and large loads, or when small spacings and small loads, were used.