To provide a method for precisely predicting the flowing state in a stirring tank without any special experiment and a method for precisely displaying the flowing state.

The space in the stirring tank 1 to be analyzed is divided into a proper number of meshes, equations which dominate a continuous expression and the kinetic momentum, energy, and substance transportation of a flow field are converted into a discrete equation group based upon a difference method, and computation based upon the discrete equation group is repeated until the flow field enters a stationary state under initial conditions and border conditions to find distributions of the flow velocity, pressure, temperature, and concentration in the stirring tank.