A sensor device includes a radio wave sensor and a signal processor. The signal processor includes an identifier and a noise remover configured to remove, from a second sensor signal, at least one frequency component determined as a noise component by the identifier. The identifier compares a signal intensity of each of the frequency components with one or more signal intensities of other frequency components. When a signal intensity of a first frequency component is greater than signal intensities of one or more second frequency components located in the vicinity of the first frequency component by an extent exceeding a threshold range, the identifier determines the first frequency component as the noise component.