In a print element substrate: if an amount of a voltage drop when the number of print elements driven simultaneously in a state in which the predetermined voltage is applied with respect to one print element array is largest is set as an amount of a voltage drop of the print element array, and a sum of amounts of voltage drops of the print element arrays assigned to one group is set as an amount of a voltage drop of the group, a difference between a largest value and a smallest value of the amounts of the voltage drops of the M groups is smaller than a largest value of the amounts of the voltage drops of the N print element arrays.