According to one embodiment, a sensor includes a film portion and a first sensor portion. The film portion is deformable. The first sensor portion is provided at the film portion. The first sensor portion includes a first conductive layer, a second conductive layer, a first magnetic layer, a second magnetic layer, and a first intermediate layer. The second conductive layer is provided between the first conductive layer and the film portion. The first magnetic layer is provided between the first conductive layer and the second conductive layer. The second magnetic layer is provided between the first magnetic layer and the second conductive layer. The first intermediate layer is provided between the first magnetic layer and the second magnetic layer. A curvature of the first conductive layer is different from a curvature of at least a portion of the film portion.