A position detecting device including an antenna function includes a plurality of electrodes including a plurality of shared electrodes separated by spaces, a position detection circuit configured to detect a position by energizing the plurality of electrodes and using electric fields generated between the plurality of electrodes, an antenna circuit configured to perform wireless communication by energizing the plurality of shared electrodes and using magnetic fields generated in the spaces, and a switch connected to at least the plurality of shared electrodes among the plurality of electrodes, the position detection circuit, and the antenna circuit, the switch being configured to selectively connect either the position detection circuit or the antenna circuit to the plurality of shared electrodes.