An optical apparatus includes first and second substrates disposed to oppose each other, the first substrate having a first electrode provided on a surface of the first substrate nearer to the second substrate, and the second substrate having a second electrode provided on a surface of the second substrate nearer to the first substrate, and an electrolyte layer sandwiched between the first and the second substrates, and containing electro-deposition material including silver, wherein when potential of the first electrode is used as reference, a first voltage of positive polarity is applied in a first period to the second electrode, and a second voltage of positive polarity lower than the first voltage is applied in a second period after the first period to the second electrode.