According to one embodiment, a sensor includes a first film, a first sensor portion, and first to fourth terminals. The first film includes first to second electrode layers, and a piezoelectric layer. The first film is deformable. The first sensor portion is fixed to a portion of the first film. A first direction from the portion of the first film toward the first sensor portion is aligned with a direction from the second electrode layer toward the first electrode layer. The first sensor portion includes first to second sensor conductive layers, first to second magnetic layers, and a first intermediate layer. The first terminal is electrically connected to the first electrode layer. The second terminal is electrically connected to the second electrode layer. The third terminal is electrically connected to the first sensor conductive layer. The fourth terminal is electrically connected to the second sensor conductive layer.