An ICP emission spectrophotometer includes an inductively coupled plasma device, a spectroscope, and a computer. The spectroscope includes an incidence window, an incidence side slit, a diffraction grating, an emission window, an emission side slit, and a detector. Measurement conditions including diffraction condition and a measurement result are displayed on a display device. In a case where there are a plurality of diffraction conditions each including a combination of a diffraction grating and a diffraction order for measuring desired diffracted light, comparison information including at least an intensity and a resolution of emitted light in the diffraction condition is displayed on the display device. A measurer selects diffraction conditions in which resolution is higher from among the diffraction conditions, and selects a diffraction condition in which an intensity is obtained from among the selected diffraction conditions.