An optical scanning apparatus comprising: a mirror having a reflective surface; a driving section that swings the mirror; a detection section that detects the movement of the driving section by change of a capacitance; and a dummy capacitance section that generates a dummy capacitance that is approximately equivalent to the capacitance in an initial state of the detection section; wherein the detection section has a movable electrode whose position changes in relation to the movement of the driving section and a fixed electrode whose position does not change in relation to the movement of the driving section, and is configured such that the capacitance is generated between the movable electrode and the fixed electrode, wherein the dummy capacitance section is configured to include a first electrode and a second electrode, and is configured to generate the dummy capacitance between the first electrode and the second electrode, wherein the movable electrode, the fixed electrode, the first electrode, and the second electrode are provided in an active layer formed in the same semiconductor layer, and are each separated, wherein the active layer is arranged to face a support layer which is a common semiconductor layer, with an insulating layer in between, wherein a first parasitic capacitance that occurs between the active layer provided with the fixed electrode and the supporting layer, and a second parasitic capacitance that occurs between the active layer provided with the first electrode and the supporting layer, are approximately equivalent, and wherein the capacitance of the detection section and the first parasitic capacitance are connected in series to form a first signal path, and the dummy capacitance and the second parasitic capacitance are connected in series to form a second signal path. a mirror having a reflective surface; a driving section that swings the mirror; a detection section that detects the movement of the driving section by change of a capacitance; and a dummy capacitance section that generates a dummy capacitance that is approximately equivalent to the capacitance in an initial state of the detection section; wherein the detection section has a movable electrode whose position changes in relation to the movement of the driving section and a fixed electrode whose position does not change in relation to the movement of the driving section, and is configured such that the capacitance is generated between the movable electrode and the fixed electrode, wherein the dummy capacitance section is configured to include a first electrode and a second electrode, and is configured to generate the dummy capacitance between the first electrode and the second electrode, wherein the movable electrode, the fixed electrode, the first electrode, and the second electrode are provided in an active layer formed in the same semiconductor layer, and are each separated, wherein the active layer is arranged to face a support layer which is a common semiconductor layer, with an insulating layer in between, wherein a first parasitic capacitance that occurs between the active layer provided with the fixed electrode and the supporting layer, and a second parasitic capacitance that occurs between the active layer provided with the first electrode and the supporting layer, are approximately equivalent, and wherein the capacitance of the detection section and the first parasitic capacitance are connected in series to form a first signal path, and the dummy capacitance and the second parasitic capacitance are connected in series to form a second signal path.