A printer-incorporated electronic still camera has a built-in optical printer for printing an image on an instant film sheet based on electronic image signals read out from a memory. The optical printer uses a fluorescent display panel as a light source of a printing head. The fluorescent display panel is constituted of an array of light emitting elements arranged in a vacuum container. Before being driven to print an image based on the electronic image signals, all of the light emitting elements are driven for a constant time to remove deposited residual gas off the light emitting elements.