A method for irradiating a target with a main pulse laser beam and a pre-pulse laser beam at timings defined by a delay time, comprising: outputting the main pulse laser beam having a first waveform (Ws), the first waveform including a first portion and a second portion, the first portion is a front portion of the first waveform (Ws), the second portion (Ws) including a peak having a peak intensity of the main pulse laser beam; transforming the main pulse laser beam from the first waveform to a second waveform by controlling an optical element to control transmission of the main pulse laser beam through the optical element, the second waveform including a transformed first portion and a transformed second portion following the transformed first portion, the transformed first portion including a pedestal, the transformed second portion including the peak having the peak intensity of the main pulse laser beam; amplifying the second waveform while maintaining connection between the transformed first portion and the transformed second portion, the amplified second waveform including an amplified first portion and an amplified second portion, the amplified first portion having a maximum energy that is less than the maximum energy of the amplified second portion; and irradiating the target with the amplified first portion and the amplified second portion; the method further comprising controlling a ratio of energy of the amplified first portion to total energy of the amplified first portion and the amplified second portion. outputting the main pulse laser beam having a first waveform (Ws), the first waveform including a first portion and a second portion, the first portion is a front portion of the first waveform (Ws), the second portion (Ws) including a peak having a peak intensity of the main pulse laser beam; the first waveform including a first portion and a second portion, the first portion is a front portion of the first waveform (Ws), the second portion (Ws) including a peak having a peak intensity of the main pulse laser beam; transforming the main pulse laser beam from the first waveform to a second waveform by controlling an optical element to control transmission of the main pulse laser beam through the optical element, the second waveform including a transformed first portion and a transformed second portion following the transformed first portion, the transformed first portion including a pedestal, the transformed second portion including the peak having the peak intensity of the main pulse laser beam; the second waveform including a transformed first portion and a transformed second portion following the transformed first portion, the transformed first portion including a pedestal, the transformed second portion including the peak having the peak intensity of the main pulse laser beam; amplifying the second waveform while maintaining connection between the transformed first portion and the transformed second portion, the amplified second waveform including an amplified first portion and an amplified second portion, the amplified first portion having a maximum energy that is less than the maximum energy of the amplified second portion; and irradiating the target with the amplified first portion and the amplified second portion; the method further comprising controlling a ratio of energy of the amplified first portion to total energy of the amplified first portion and the amplified second portion.