An element chip manufacturing method including: a preparing step of preparing a substrate including a plurality of element regions and a dicing region defining the element regions, the substrate having a first surface and a second surface opposite the first surface; a laser scribing step of applying a laser beam to the dicing region from a side of the first surface, to form a groove corresponding to the dicing region and being shallower than a thickness of the substrate; a cleaning step of exposing the first surface of the substrate to a first plasma, to remove debris on the groove; and a dicing step of exposing the substrate at a bottom of the groove to a second plasma after the cleaning step, to dice the substrate into element chips including the element regions. The first plasma is generated from a process gas containing a carbon oxide gas.