To provide an ion implantation dose monitoring method for monitoring the dose stably in a wide range inexpensively.

After implanting fluorine ion F+ at different doses into one or a plurality of standard silicon substrates, a thermal oxidation process is applied to each ion implanter to form a silicon oxide film, and the oxide film thickness is measured to form reference data showing the relation between the dose and the oxide film thickness, as show in Fig. 4. After implanting fluorine ion F+ into the standard silicon substrate, a thermal oxidation process is applied to the ion implanter to form a silicon oxide film, and the oxide film thickness is measured to obtain the dose of fluorine ion corresponding to the measured oxide film thickness by referring to the standard data. About a silicon nitride film or a silicon oxide nitride film covering the substrate, the dose of argon ion Ar+, etc. can be monitored similarly, as described above.