An external-force detecting apparatus comprising: an oscillator including one or more drive electrodes (101 to 104) and one or more monitor electrodes (91, 92), and at least one of the drive electrodes (101 to 104) and the monitor electrodes (91, 92) are two or more; a driving unit driving the oscillator wherein the driving unit includes a drive circuit part and a detection circuit part; one or more drive lines that are provided for the respective drive electrodes (101 to 104) and that connect the corresponding drive electrodes (101 to 104) to the driving unit; and one or more monitor lines that are provided for the respective monitor electrodes (91, 92) and that connect the corresponding monitor electrodes (91, 92) to the driving unit, wherein the driving unit outputs a drive signal to the one or more of the drive electrodes (101 to 104) through the one or more of the drive lines to drive the oscillator and performs automatic gain control to the level of the drive signal on the basis of the oscillation state of the oscillator acquired from the one or more of the monitor electrodes (91, 92) through the one or more of the monitor lines, the external-force detecting apparatus further comprising: a first switching circuit (25, 26, 27, 28) switching connection and disconnection of an electric path between the oscillator and the driving unit via at least one of the multiple drive lines or the multiple monitor lines, characterized in that the first switching circuit (25, 26, 27, 28) switches connection and disconnection of a drive line between one of the two or more of drive electrodes (101 to 104) and the drive circuit part, or connection and disconnection of a monitor line between an output of one of the two or more monitor electrodes (91, 92) and an input of the detection circuit part. an oscillator including one or more drive electrodes (101 to 104) and one or more monitor electrodes (91, 92), and at least one of the drive electrodes (101 to 104) and the monitor electrodes (91, 92) are two or more; a driving unit driving the oscillator wherein the driving unit includes a drive circuit part and a detection circuit part; one or more drive lines that are provided for the respective drive electrodes (101 to 104) and that connect the corresponding drive electrodes (101 to 104) to the driving unit; and one or more monitor lines that are provided for the respective monitor electrodes (91, 92) and that connect the corresponding monitor electrodes (91, 92) to the driving unit, wherein the driving unit outputs a drive signal to the one or more of the drive electrodes (101 to 104) through the one or more of the drive lines to drive the oscillator and performs automatic gain control to the level of the drive signal on the basis of the oscillation state of the oscillator acquired from the one or more of the monitor electrodes (91, 92) through the one or more of the monitor lines, the external-force detecting apparatus further comprising: a first switching circuit (25, 26, 27, 28) switching connection and disconnection of an electric path between the oscillator and the driving unit via at least one of the multiple drive lines or the multiple monitor lines, characterized in that the first switching circuit (25, 26, 27, 28) switches connection and disconnection of a drive line between one of the two or more of drive electrodes (101 to 104) and the drive circuit part, or connection and disconnection of a monitor line between an output of one of the two or more monitor electrodes (91, 92) and an input of the detection circuit part. a first switching circuit (25, 26, 27, 28) switching connection and disconnection of an electric path between the oscillator and the driving unit via at least one of the multiple drive lines or the multiple monitor lines, characterized in that the first switching circuit (25, 26, 27, 28) switches connection and disconnection of a drive line between one of the two or more of drive electrodes (101 to 104) and the drive circuit part, or connection and disconnection of a monitor line between an output of one of the two or more monitor electrodes (91, 92) and an input of the detection circuit part.