An accelerometer includes a fixing unit and a movable unit. The fixing unit has a plurality of first electrode parts and a plurality of second electrode parts. The movable unit is connected with the fixing unit and includes a body having an opening, a plurality of third electrode parts and a plurality of fourth electrode parts. The third electrode parts are disposed at an outer side of the body with respect to the first electrode parts, respectively. The fourth electrode parts are disposed at the inner side of the body in the opening, and are disposed respectively with respect to the second electrode parts, respectively.