An automatic IC mounting process for mounting a plurality of ICs on an upper surface of a printed circuit board in accordance with a predetermined sequence program. Each of the ICs has a plurality of leads, each of which is to be inserted into a predetermined corresponding through-hole of the printed circuit board. The process includes: (i) a step for inserting the leads of an IC into the through-holes of the printed circuit board; (ii) a step for detecting whether or not each lead of the IC is correctly inserted into the corresponding through-hole after every step (i); (iii) a step for removing a misinserted IC having a misinserted lead from the printed circuit board and discarding the misinserted IC into a predetermined reject place immediately after a misinsertion is detected in the step (ii); (iv) a step for memorizing the information for identifying the misinserted IC; (v) a step for mounting a predetermined number of subsequent ICs on the printed circuit board in accordance with the predetermined sequence program, leaving the position of the misinserted IC unmounted; (vi) a step for searching for whether or not the information was memorized in the step (iv); and, (vii) a step for preparing a new IC identified by that information and remounting it on the printed circuit board at the position of the misinserted IC.