Resonance device

A resonance device comprising:

• a vibrator layer having:
• a vibration portion including a plurality of vibration arms and a base portion;
• a holding portion configured to hold the vibration portion;
• and
• a holding arm that connects the vibration portion to the holding portion,
• the plurality of vibration arms having a piezoelectric layer, first electrode layer on a first main surface of the piezoelectric layer, and a second electrode layer on a second main surface of the piezoelectric layer opposite to the first main surface,
• a fixed end of each of the plurality of vibration arms being connected to the base portion,
• the plurality of vibration arms have at least one inside vibration arm and at least two outside vibration arms each respectively disposed on opposite outer sides of the inside vibration arm in a plan view of the vibrator layer, and
• the inside vibration arm and the outside vibration arms are configured to be capable of out-of-plane bending vibration with phases different from each other;
• a first cover layer on a side of the first electrode layer of the vibrator layer;
• and
• a second cover layer on a side of the second electrode layer of the vibrator layer;
• and
• a first external terminal and a second external terminal on either the first cover layer or the second cover layer on an opposite side thereof to a side facing the vibrator layer, wherein
• in one of the inside vibration arm and the outside vibration arms, the first electrode layer and the second electrode layer are both electrically connected to the first external terminal, and
• in the other of the inside vibration arm and the outside vibration arms, one of the first electrode layer and the second electrode layer is electrically connected to the first external terminal and the other of the first electrode layer and the second electrode layer is electrically connected to the second external terminal.