An object cutting method which can reliably remove particles remaining on cut sections of chips is provided. An expandable tape 23 is electrically charged in a state where a plurality of semiconductor chips 25 obtained by cutting a planar object to be processed along a line to cut are separated from each other on the expandable tape 23. This electric action causes particles remaining on cut sections of the semiconductor chips 25 to eject therefrom even when a molten processed region is formed in the cut sections. Therefore, particles remaining on the cut sections of the chips 25 can reliably be removed.