Cell treatment method, laser processing machine, and cell culture vessel

A method of killing specific cells from among a group of cells cultured in a vessel comprising a main body and a layer attached to the main body, wherein the layer contains an ingredient capable of generating heat upon laser irradiation and the group of cells are cultured on the top surface of the layer, the method comprising applying a laser light to a partial area of the bottom surface of the layer by moving the laser light along a plane parallel to the partial area, wherein:

• the partial area of the layer irradiated with the laser light absorbs energy of the laser light and thereby generates heat that kills unwanted cells that are present directly above the partial area,
• the laser light does not instantly kill the specific cells upon irradiation,
• the laser light output is 5 W or less,
• the laser light wavelength is 380 nm or greater,
• the laser light moving rate is 2000 mm/sec or less, and
• the thickness of the layer is 10 mm or less.