There is provided an image acquisition device including a light source configured to emit laser light and to be capable of controlling a wavelength of the laser light, a measurement unit configured to scan a sample using the laser light and to measure an intensity of measurement target light from the sample by receiving the laser light, and a control unit configured to generate an image of the sample based on intensity distribution of the measured measurement target light. The control unit controls a wavelength of the laser light based on the intensity distribution of the measured measurement target light.