1. A computerized analysis method for estimating a kneaded state of a fluid, comprising: a step of generating a kneading space model which is a finite element model of a kneading space within which the fluid is kneaded, a step of defining a fluid model of the fluid, a step of defining the fluid model in the kneading space model at a filling rate of less than 100% and defining necessary kneading conditions, a particle tracking step in which, a flow calculation of the fluid model is made based on the kneading conditions, and virtual particles disposed in the fluid model are tracked, and an estimating step in which the positional data of the virtual particles are compared with those in an ideal kneaded state of the fluid model, and the degree of kneading of the fluid model is calculated, wherein the ideal kneaded state is calculated in the estimating step, based on existence positions of the fluid model calculated in the particle tracking step.