A tablet printing device, comprising: a conveyer configured to convey tablets along a line in a conveyance direction; an applicator head including a plurality of nozzles arranged in a direction crossing the conveyance direction of the tablets conveyed by the conveyer, configured to perform printing on the tablets by ejecting a liquid from the nozzles; a horizontal movement device configured to move the applicator head in the direction perpendicular to the conveyance direction; and a controller configured to control ejection of the liquid from the nozzles of the applicator head, wherein the nozzles of the applicator head are divided into a plurality of sections (A, B, C) determined in advance, a length of an array of the nozzles in the direction perpendicular to the conveyance direction in each of the sections (A, B, C) is equal to or longer than a length of each of the tablets in the direction perpendicular to the conveyance direction, and the controller is further configured to control switching of the nozzles such that the nozzles used for printing on the tablets are switched among the nozzles by controlling the horizontal movement device to move the applicator head by a length of each of the sections (A, B, C) or by an integer multiple of said length to perform switching of the sections (A, B, C) when a preset time has elapsed after start of printing or when the nozzles are driven a preset number of times, until the nozzles in all the sections (A, B, C) face the line by the switching and specifying the one of the sections (A, B, C) that faces the line to perform printing on the tablets conveyed along the line. a conveyer configured to convey tablets along a line in a conveyance direction; an applicator head including a plurality of nozzles arranged in a direction crossing the conveyance direction of the tablets conveyed by the conveyer, configured to perform printing on the tablets by ejecting a liquid from the nozzles; a horizontal movement device configured to move the applicator head in the direction perpendicular to the conveyance direction; and a controller configured to control ejection of the liquid from the nozzles of the applicator head, wherein the nozzles of the applicator head are divided into a plurality of sections (A, B, C) determined in advance, a length of an array of the nozzles in the direction perpendicular to the conveyance direction in each of the sections (A, B, C) is equal to or longer than a length of each of the tablets in the direction perpendicular to the conveyance direction, and the controller is further configured to control switching of the nozzles such that the nozzles used for printing on the tablets are switched among the nozzles by controlling the horizontal movement device to move the applicator head by a length of each of the sections (A, B, C) or by an integer multiple of said length to perform switching of the sections (A, B, C) when a preset time has elapsed after start of printing or when the nozzles are driven a preset number of times, until the nozzles in all the sections (A, B, C) face the line by the switching and specifying the one of the sections (A, B, C) that faces the line to perform printing on the tablets conveyed along the line.