A series of degree-of-approach data of the same object generated over a plurality of cycles of a detection operation is averaged in filter processing of the filter processing unit, and accordingly, the degree-of-approach data after averaging is acquired. Therefore, even in a case in which the degree-of-approach data is temporarily greatly changed due to an influence of noise, such a temporary change in the degree-of-approach data after averaging is suppressed. Further, response characteristics of a filter in the filter processing of the filter unit are changed according to a noise level which is detected by a noise detection unit. Accordingly, since appropriate filter processing according to the noise level is performed on the degree-of-approach data, the degree-of-approach data in which the influence of noise is effectively reduced is obtained.