correction energy correction and adjusted oscillation the number 602 of oscillation command pulses is the integrated value of the number of oscillation pulses instructed from the main control software 302 built in the main controller 109 of the exposure device 150 to the laser control software 301 built in the laser controller 109 the number 602 of oscillation command pulses is updated by the main control software 302 at each oscillation when a maintenance process is performed the number 602 of oscillation command pulses is cleared to zero by the maintenance control software 303 preset duty described as u201c set duty u201d as well in this specification 604 indicates the proportion of laser oscillation time in preset time 603 the operator can arbitrarily set the preset duty 604 through the operation system software 304 for each maintenance item a maintenance state 605 indicates the current state of a given maintenance item 601 and can be u201c a normal state u201d u201c executing maintenance u201d or u201c maintenance requested u201d fig6 is a flowchart showing the flow of a process that the maintenance control software 303 executes upon reception of the maintenance request notification 307 from the laser control software 301 in step s 701 it is checked whether the maintenance request is made because a specified number of pulses has been oscillated or a specified time has elapsed this determination can be.