When color measurement is performed, a printer driver of a host apparatus 150 transmits a job start command “JS” to a printer 10, then performs printing instruction (print data transmission for color measurement printing), color measurement instruction, reception of a color measurement result (color measurement data) from a color measuring device (a color meter 41 and a color measurement driving device 80), label printing instruction, job information storage instruction, and positioning instruction, and subsequently transmits a job end command “JE” to the printer 10. During a period from the job start command “JS” until the job end command “JE” is received, a communication connect between the printer 10 and the host apparatus 150 is maintained while an interrupt from other than the host apparatus 150 is inhibited.