Printing light beams from a printing head that is driven based on image data are used for recording a latent image in a predetermined exposure area on an instant film. The instant film is exposed through an exposure opening formed through a case of a film pack. The printing head projects the printing light beams linearly along a main scan direction while moving in a sub scan direction perpendicular to the main scan direction. An illumination range of the printing light beams is determined to be wider than the exposure area in the main and sub scan directions, in consideration of clearances between the case and the instant film. So the entire exposure area is exposed even where the instant film deviates inside the case. A light-shielding housing for covering up a moving range of the printing head in a light-tight fashion is formed integrally with a pack loading chamber for loading the film pack.