A maintenance device includes a plurality of heads that discharges liquid for printing. A cleaner selectively cleans the heads. A cleaning controller controls the cleaner. A determiner determines a cleaning time when the cleaner cleans one of the heads. An interruption-resumption controller controls the heads to interrupt printing at the cleaning time and resume printing when the cleaner finishes cleaning the one of the heads. The cleaning controller controls the cleaner to clean the one of the heads whenever the interruption-resumption controller controls the heads to interrupt printing at the cleaning time.