A vibrating device comprising: a dust-screening member (119, 118) having at least one side that is symmetric with respect to a symmetry axis; two vibrating members arranged along two arbitrary opposing sides of to the dust-screening member and configured to produce, at the dust-screening member, vibration having a vibrational amplitude perpendicular to a surface of the dust-screening member; and a drive circuit configured for driving the vibrating members, wherein the drive circuit is configured to drive the vibrating members to produce vibration Z (x, y) at the dust-screening member, the vibration being expressed as follows: Z x, y = W mn x, y ⋅ cos γ + W nm x, y ⋅ sin γ where Z (x, y) is vibration at a given point P (x, y) on the dust-screening member; m and n are positive integers including 0, indicating the order of natural vibration corresponding to a vibrational mode; W mn x, y = sin n π ⋅ x + π 2 ⋅ sin m π ⋅ y + π 2; W nm x, y = sin m π ⋅ x + π 2 ⋅ sin n π ⋅ y + π 2; where m is an order in direction x, and n is an order in direction y, γ, which is a given phase angle, is +π/4 or ranges from -n/8 to -n/4, wherein: the drive circuit generates frequency for producing vibration defined by γ, m, n, the vibrating member being driven by the generated frequency, when γ is +π/4, the drive circuit is configured to cause the dust-screening member to produce vibration such that peak ridges of the vibration having a vibrational amplitude perpendicular to the surface of the dust-screening member form closed loops; and when γ ranges from -π/8 to -π/4, the drive circuit is configured to cause the dust-screening member to produce vibration such that peak ridges of the vibration having a vibrational amplitude perpendicular to the surface of the dust-screening member form curves around a midpoint of the side which the dust-screening member has. a dust-screening member (119, 118) having at least one side that is symmetric with respect to a symmetry axis; two vibrating members arranged along two arbitrary opposing sides of to the dust-screening member and configured to produce, at the dust-screening member, vibration having a vibrational amplitude perpendicular to a surface of the dust-screening member; and a drive circuit configured for driving the vibrating members, wherein the drive circuit is configured to drive the vibrating members to produce vibration Z (x, y) at the dust-screening member, the vibration being expressed as follows: Z x, y = W mn x, y ⋅ cos γ + W nm x, y ⋅ sin γ where Z (x, y) is vibration at a given point P (x, y) on the dust-screening member; m and n are positive integers including 0, indicating the order of natural vibration corresponding to a vibrational mode; W mn x, y = sin n π ⋅ x + π 2 ⋅ sin m π ⋅ y + π 2; W nm x, y = sin m π ⋅ x + π 2 ⋅ sin n π ⋅ y + π 2; where m is an order in direction x, and n is an order in direction y, γ, which is a given phase angle, is +π/4 or ranges from -n/8 to -n/4, wherein: the drive circuit generates frequency for producing vibration defined by γ, m, n, the vibrating member being driven by the generated frequency, when γ is +π/4, the drive circuit is configured to cause the dust-screening member to produce vibration such that peak ridges of the vibration having a vibrational amplitude perpendicular to the surface of the dust-screening member form closed loops; and when γ ranges from -π/8 to -π/4, the drive circuit is configured to cause the dust-screening member to produce vibration such that peak ridges of the vibration having a vibrational amplitude perpendicular to the surface of the dust-screening member form curves around a midpoint of the side which the dust-screening member has. where m is an order in direction x, and n is an order in direction y, γ, which is a given phase angle, is +π/4 or ranges from -n/8 to -n/4, wherein: the drive circuit generates frequency for producing vibration defined by γ, m, n, the vibrating member being driven by the generated frequency, when γ is +π/4, the drive circuit is configured to cause the dust-screening member to produce vibration such that peak ridges of the vibration having a vibrational amplitude perpendicular to the surface of the dust-screening member form closed loops; and when γ ranges from -π/8 to -π/4, the drive circuit is configured to cause the dust-screening member to produce vibration such that peak ridges of the vibration having a vibrational amplitude perpendicular to the surface of the dust-screening member form curves around a midpoint of the side which the dust-screening member has. the drive circuit generates frequency for producing vibration defined by γ, m, n, the vibrating member being driven by the generated frequency, when γ is +π/4, the drive circuit is configured to cause the dust-screening member to produce vibration such that peak ridges of the vibration having a vibrational amplitude perpendicular to the surface of the dust-screening member form closed loops; and when γ ranges from -π/8 to -π/4, the drive circuit is configured to cause the dust-screening member to produce vibration such that peak ridges of the vibration having a vibrational amplitude perpendicular to the surface of the dust-screening member form curves around a midpoint of the side which the dust-screening member has.