A printer has a base, a cover, a touch panel, a printing module and a detachable bracket. The base has two mounting rails. Each mounting rail has an engaging slot and an engaging protrusion. The cover is mounted detachably on the base. The touch panel is mounted on the base. The printing module is mounted detachably on the base and covered by the cover. The detachable bracket is mounted securely on the printing module and has a bottom plate and two opposite side plates. Each side plate has an engaging tab and an engaging notch detachably engaging the engaging slot and protrusion of a corresponding mounting rail. The printer with the mounting rails and detachable bracket allows the printing module to be repaired independently without disassembling the touch panel.