To provide a light-stimulus illumination apparatus which can apply a light stimulus to a plurality of spatially separated regions within a short period of time.

The light-stimulus illumination apparatus includes: a light source 14 for emitting light-stimulus laser light L1; a scanning means 15 which scans the light-stimulus laser light L1 emitted from the light source 14 in a direction of intersecting an optical axis and is provided with at least one acousto-optic element 15a, 15b; and a control means 20 for controlling the scanning means 15, wherein the control means 20 controls the scanning means 15 so as to irradiate the plurality of spatially separated regions with the light-stimulus laser light L1 time-divisionally.