Printhead structured such that printing elements are divisionally driven in unit of plural blocks, comprises: an input terminal to which printing data and encoded block data are serially inputted; a shift register sequentially shifting and storing one bit at a time the data serially inputted from the input terminal; a latch temporarily storing the data stored in the shift register; a decoder decoding the block data stored in the latch; and an AND circuit. The decoder outputs a signal in which encoded block data is partially decoded, and the AND circuit determines blocks to be driven based on the partially decoded signal. This structure enables to reduce an area of a printhead substrate, thereby enabling cost reduction of a printhead.