The invention relates to a method for putting color to glass. This method includes the steps of (a) introducing a laser beam into an interferometer such that the laser beam is split into at least first and second laser beams in the interferometer and that the at least first and second laser beams come out of the interferometer; and (b) irradiating a glass with the at least first and second laser beams to write a plurality of lines simultaneously on a surface of the glass and/or in an inside of the glass.