A printer includes a light source module including an ejecting head that ejects a UV ink onto a medium. The UV ink hardens when irradiated with a UV light ray. The light source module includes an irradiator that irradiates the UV ink with the UV light ray. The printer may include a guide shaft to/from which the light module is attachable/detachable and a driving controller that performs control of the irradiator. The light source module includes, in addition to the irradiator, a memory module that stores therein information indicating a light irradiation feature of the irradiator. The driving controller performs control of the irradiator by using the information indicating a light irradiation feature of the irradiator.