According to one embodiment, a sensor includes a deformable film portion, and a first sensing element provided at the film portion. The first sensing element includes a first magnetic layer, a second magnetic layer, and a first intermediate layer provided between the first and second magnetic layers. The first intermediate layer is nonmagnetic. The first magnetic layer includes a first film including Fe and Co, a second film including Fe and Co, a third film, and a fourth film. The third film includes at least one selected from the group consisting of Cu, Au, Ru, Ag, Pt, Pd, Ir, Rh, Re, and Os and is provided between the first and second films. The fourth film includes at least one selected from the group consisting of Mg, Ca, Sc, Ti, Sr, Y, Zr, Nb, Mo, Ba, La, Hf, Ta, and W and is provided between the third and second films.
