In a load transfer mechanism which transfers load to a load cell that constitutes a Roberval mechanism, a load transfer member has at least an area right above a load cell mounting section in the top surface thereof as a concave surface area formed to be lower than the remaining area of the top surface thereof so that it does not contact a cover member. Thus, if the barycentric position of the load of an object to be weighed placed on the cover member, regardless of whether the load is concentrated load or divided load, the load transfer mechanism can reduce the difference of the influence of deflection of the load transfer member or moment imposed on the load, transfer given load to the load cell through the load transfer member and decrease a span error produced by the load position of an object to be weighed.