A tablet printing device includes a first conveying disk that conveys a tablet while sucking and supporting a side surface of the tablet and an inkjet head capable of applying print processing to the front and back surfaces of the tablet conveyed by the conveying disk. The tablet is conveyed while being supported by a second conveying disk at its front and back surfaces and subjected to inspection of the side surface by a side surface inspection device. The tablet is transferred from the second conveying disk to the first conveying disk at a tablet delivery part and then supported by a suction hole formed in an end surface of the first conveying disk with the front and back surfaces fully exposed. The front and back surfaces are subjected to print processing ead, followed by print inspection, and only a non-defective tablet is discharged through a non-defective tablet discharge part.