A medical image formation apparatus includes laser emitting elements which emit laser light rays different in wavelength, an image selection circuit to select a kind of observation image, a light source controller which controls the laser emitting elements, in accordance with an observation mode corresponding to the selected kind, an imager which images return light ray from an observation target and then outputs the return light ray as an image signal, and an image processor which forms the observation images. A first laser emitting group is controlled when the kind of selected observation image is a first observation image. A second laser emitting group is controlled when the kind of selected observation image is a second observation image. The first laser emitting group and the second laser emitting group include a first common laser emitting element.