A pair of vibrating arm portions are disposed lined up in a second direction perpendicular to a first direction and are configured such that base end sides thereof in the first direction are fixed to a base portion. A pair of inclined surfaces are formed on both sides in the second direction on the base end side of the vibrating arm portion so that a width of the vibrating arm portion in the second direction is gradually widened from the distal end side to the base end side. A length of a region, having the pair of inclined surfaces formed therein, in the first direction is set to equal to or greater than 0.25 times and equal to or less than 0.5 times of a total length of the vibrating arm portion from the base end to the distal end.