According to one embodiment, a sensor includes a base body, a support portion fixed to the base body, and a first member supported by the support portion. A gap is provided between the base body and a part of the first member. The first member includes a supported region, a first movable region, a first structure, a first support structure, a first connection structure, a first connect portion, and a first beam. The support portion is located between the base body and the supported region in a first direction from the base body to the support portion. The first beam extends along a second direction crossing the first direction. A first beam position of the first beam is located between a first movable region position of the first movable region and a support portion position of the support portion in the second direction.