The invention provides a weight measuring apparatus which carries out zero-point reset as an output value of a load signal in an unloaded state when the weight measuring apparatus is not in use, including a weight measuring unit that measures a load applied to a machine body and outputs the load signals; and a control device that receives the load signals from the weight measuring unit at reset time intervals for carrying out the zero-point reset of the weight measuring unit in the unloaded state, in which the control device changes the reset time interval to next zero-point reset according to the difference between the output value of the load signal at the time of previous zero-point reset and the output value of the load signal at zero-point reset of this time.