Mass flow controllers and methods for controlling mass flow rates are disclosed. A mass flow controller includes a pressure value measurement means that measures one or two or more pressure values derived from pressure P1 of fluid on an upstream side of a pressure difference generate means and pressure P2 of the fluid on a downstream side of the pressure difference generate means, an acceleration means accelerates time variation of the obtained pressure values, a flow meter calculates a flow rate of the fluid based on a pressure value obtained according to the accelerated time variation (accelerated pressure value), and a flow control valve controls the flow rate of the fluid based on the calculated flow rate.