PURPOSE: To obtain a thermal head with a high reliability which is interchangeable with the convensional equipment by arranging an intergrated circuit having at least two different shift register values in one block to form a thermal head.

CONSTITUTION: Integrated circuits driving heat generating resistors are arranged on a plurality of substrates and divided into several blocks in each of which the operation of several integrated circuits is controlled while integrated circuits having more than one different shift register values are mounted in each block to form a thermal head. To be more specific, the ICs being used have output terminals (m=32) which output image signals inputted from an image signal input terminal after passing through a 32-bit shift register and output terminals (m= 48) which output those after passing through a 16-bit shift register.